fixed Mysql fallback for PathFinder::Sphinx::Query:
* ThinkingSphinx 2 raises Riddle::ConnectionError (not sure if ThinkingSphinx::ConnectionError may also be raised in some cases, so catching both)
* PathFinder::Mysql::Builder is called PathFinder::Mysql::Query now
use Sphinx to search through me/pages
save WikiPage after updating Wiki, to cause PageTerms to be updated
fixed PageTrackingObserverTest (was broken due to changes to Wiki model)
Merge pull request #53 from Crabgrass/feature/4189-fix-sphinx-search

fix sphinx search