Use local openssl and openssl-sys crates patched for LibreSSL 2.6.3.

--- a/Cargo.toml
+++ b/Cargo.toml
@@ -75,3 +75,7 @@
 name = "cargo"
 test = false
 doc = false
+
+[replace]
+"openssl:0.9.20" = { path = "openssl/openssl" }
+"openssl-sys:0.9.20" = { path = "openssl/openssl-sys" }
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -30,7 +30,7 @@
  "log 0.3.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "miow 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "num_cpus 1.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "psapi-sys 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "same-file 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "scoped-tls 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -138,6 +138,11 @@
 ]
 
 [[package]]
+name = "cc"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
 name = "cfg-if"
 version = "0.1.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -200,7 +205,7 @@
  "curl-sys 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "openssl-probe 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "socket2 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
@@ -213,7 +218,7 @@
  "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "libz-sys 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
  "vcpkg 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "winapi 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -318,7 +323,7 @@
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "libgit2-sys 0.6.12 (registry+https://github.com/rust-lang/crates.io-index)",
  "openssl-probe 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "url 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -445,7 +450,7 @@
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "libssh2-sys 0.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "libz-sys 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -457,7 +462,7 @@
  "cmake 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "libz-sys 1.0.16 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
@@ -623,32 +628,43 @@
 
 [[package]]
 name = "openssl"
-version = "0.9.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+version = "0.9.20"
 dependencies = [
  "bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "foreign-types 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 0.2.8 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
- "openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)",
+ "openssl-sys 0.9.20",
 ]
 
 [[package]]
+name = "openssl"
+version = "0.9.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+replace = "openssl 0.9.20"
+
+[[package]]
 name = "openssl-probe"
 version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
 name = "openssl-sys"
-version = "0.9.15"
-source = "registry+https://github.com/rust-lang/crates.io-index"
+version = "0.9.20"
 dependencies = [
- "gcc 0.3.51 (registry+https://github.com/rust-lang/crates.io-index)",
+ "cc 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
  "libc 0.2.28 (registry+https://github.com/rust-lang/crates.io-index)",
  "pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)",
+ "vcpkg 0.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
+name = "openssl-sys"
+version = "0.9.20"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+replace = "openssl-sys 0.9.20"
+
+[[package]]
 name = "percent-encoding"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
@@ -1013,6 +1029,7 @@
 "checksum bitflags 0.7.0 (registry+https://github.com/rust-lang/crates.io-index)" = "aad18937a628ec6abcd26d1489012cc0e18c21798210f491af69ded9b881106d"
 "checksum bitflags 0.9.1 (registry+https://github.com/rust-lang/crates.io-index)" = "4efd02e230a02e18f92fc2735f44597385ed02ad8f831e7c1c1156ee5e1ab3a5"
 "checksum bufstream 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "f2f382711e76b9de6c744cc00d0497baba02fb00a787f088c879f01d09468e32"
+"checksum cc 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "a9b13a57efd6b30ecd6598ebdb302cca617930b5470647570468a65d12ef9719"
 "checksum cfg-if 0.1.2 (registry+https://github.com/rust-lang/crates.io-index)" = "d4c819a1287eb618df47cc647173c5c4c66ba19d888a6e50d605672aed3140de"
 "checksum cmake 0.1.24 (registry+https://github.com/rust-lang/crates.io-index)" = "b8ebbb35d3dc9cd09497168f33de1acb79b265d350ab0ac34133b98f8509af1f"
 "checksum conv 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)" = "78ff10625fd0ac447827aa30ea8b861fead473bb60aeb73af6c1c58caf0d1299"
@@ -1067,9 +1084,9 @@
 "checksum num-rational 0.1.39 (registry+https://github.com/rust-lang/crates.io-index)" = "288629c76fac4b33556f4b7ab57ba21ae202da65ba8b77466e6d598e31990790"
 "checksum num-traits 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)" = "99843c856d68d8b4313b03a17e33c4bb42ae8f6610ea81b28abe076ac721b9b0"
 "checksum num_cpus 1.6.2 (registry+https://github.com/rust-lang/crates.io-index)" = "aec53c34f2d0247c5ca5d32cca1478762f301740468ee9ee6dcb7a0dd7a0c584"
-"checksum openssl 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)" = "f776f1d8af832fd2c637ee182c801e8f7ea8895718a2be9914cca001f6e2c40a"
+"checksum openssl 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)" = "8bf434ff6117485dc16478d77a4f5c84eccc9c3645c4da8323b287ad6a15a638"
 "checksum openssl-probe 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "d98df0270d404ccd3c050a41d579c52d1db15375168bb3471e04ec0f5f378daf"
-"checksum openssl-sys 0.9.15 (registry+https://github.com/rust-lang/crates.io-index)" = "ad95f8160d1c150c4f44d4c4959732e048ac046c37f597fe362f8bf57561ffb4"
+"checksum openssl-sys 0.9.20 (registry+https://github.com/rust-lang/crates.io-index)" = "0ad395f1cee51b64a8d07cc8063498dc7554db62d5f3ca87a67f4eed2791d0c8"
 "checksum percent-encoding 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "de154f638187706bde41d9b4738748933d64e6b37bdbffc0b47a97d16a6ae356"
 "checksum pkg-config 0.3.9 (registry+https://github.com/rust-lang/crates.io-index)" = "3a8b4c6b8165cd1a1cd4b9b120978131389f64bdaf456435caa41e630edba903"
 "checksum psapi-sys 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "abcd5d1a07d360e29727f757a9decb3ce8bc6e0efa8969cfaad669a8317a2478"