When fresh CRLs are released with a high update frequency (e.g.
every 24 hours) or OCSP is used then the certificate cache gets
quickly filled with stale CRLs or OCSP responses. The new VICI
flush-certs command allows to flush e.g. cached CRLs or OCSP
responses only. Without the type argument all kind of certificates
(e.g. also received end entity and intermediate CA certificates)
are purged.

This allows redirecting IKE_SAs by multiple different selectors, if none
are given all SAs are redirected.

- Switch.pm, which was implemented as a source filter, has been deprecated in
  Perl 5.10 and was later removed from the core modules in Perl 5.14 or so.

  Unfortunately, its replacement, the given/when/default construct, has since
  been downgraded to "experimental" status because of problems with the underlying
  "smart-match" operator.

  Thus, as of Perl 5.22, Perl still has no actually usable "switch"-like construct.

  So just use boring, old and ugly "if/elsif/else" constructs instead, which are
  compatible with almost any Perl version.

- None of the Perl modules here does anything that would require "AutoLoader".

- "Exporter" can be used to export plain functions into another modules name
  space. But the things that were exported here are meant to be called as
  methods.  In this case, it is neither necessary nor advisable to export those
  symbols.

  Just export nothing (the POD documentation already said so).

- It is usually the calling script that enables (or does not enable) warnings
  globally. When a module says "use warnings;" however, the caller looses control
  over what warnings should be enabled in that module.

This is called when running `make distclean` (or indirectly via `make
distcheck`).