openssl binary may be missing while migrating system from libressl to
openssl. Make sure we can always sign the backage if either is there.

packages should never depend on themselves which does not make sense.
This may happen if main package depends on a subpackage, then the
subpackages will inherit the global depends and the subpackage ends up
depend on itself.

Fix abuild to avoid this.

The 'Compressing data' step takes a significant amount of time when
packaging software with huge binaries, like Kubernetes. This can
certainly be shortened using multithreaded compression, like 'pigz'.

Symbolic links might point to files outside of the chroot and
thus might delete files outside the chroot. This allows deletion
of arbitrary directories on the host from a malicious APKBUILD.

Following hard links shouldn't be a problem since hard links (usually)
cannot refer to directories and since remove(3) removes the link, not
the file it points to it shouldn't cause a problem.

I noticed this because alpine-baselayout creates /var/run as a symlink
to /run. Therefore causing /run to be deleted on the host when using
abuild-rmtemp which in turn causes a bunch of software to no longer
function properly (including OpenRC).