Issue #1996004 by greg.1.anderson: catch exception thrown in sql-conf when database is configured but empty.
Issue #1999644 by PawelR: Fixed Misleading error message when PHP version is incompatible.
Add static cache to autocomplete, to avoid cache misses when detected
site/root change after bootstrap.
Issue #1785072 by Owen Barton: when site is set, autocomplete doesn't work identical to when using the alias directly
Issue #602182 by Dave Reid, John Morahan: Fixed updatedb should clear cache.