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
Replace stringstream with a std::string in ModeParser::Process()

There is no benefit in using a stringstream here
Change mode_sequence to be a const ref in ModeParser::Process()

Also change the signature of DisplayListModes() to accept a const ref
Add Modes::Change and Modes::ChangeList
Populate a Modes::ChangeList object in ModeParser::Process()
Pass the modes to the OnMode hook as a Modes::ChangeList, pass ModeProcessFlags too
m_spanningtree Add function to serialize parameters in a Modes::ChangeList::List into MODE/FMODE format
m_spanningtree Send MODE/FMODE from the OnMode hook

If the MODE_LOCALONLY flag is set the mode change is not propagated
Remove ProtocolInterface::SendMode()
Compare Limits.MaxModes to the size of LastChangeList in ModeParser::Process()
Remove ModeParser::LastParseParams and GetLastParseParams()
Remove ModeParser::LastParseTranslate and GetLastParseTranslate()
Remove ModeHandler::m_paramtype and GetTranslateType()