Fix listmodes when the config does not specify a wildcard size entry.
Merge pull request #899 from SaberUK/insp20+fix-listmode-limits

[2.0] Fix listmodes when the config does not specify a wildcard size entry.
Fix pkg-config not being used for OpenSSL on non-FreeBSD systems.
Add a work around for trampling over PKG_CONFIG_PATH.

The extend_pkg_path method will be removed in 2.2 as it
causes problems with non-standard pkg-config paths. This
commit adds a workaround until that happens.
Merge pull request #900 from SaberUK/insp20+build-system-fixes

[2.0] Fix various problems with the build system.
Fix unit-cc not loading configure cache when building files.
Merge pull request #910 from SaberUK/insp20+even-more-build-system-fixes

Fix unit-cc not loading configure cache when building files.
m_sqlite3 Fix cleanup of unsuccessful database connections
Do not use the result of the dns cache when the query type of the result is different from the type of the query. #66
Remove IPv6 address compaction.

This code is incorrect and can produce addresses with multiple double
colons. No other IRCds do this and most systems today will give us the
compact version anyway.

Issue #914
Fix hash_map.h on non-GNU C++ standard library implementations.