Page titles report improvements fixes #1898

 * new fields in 2 log tables (major schema upgrade in next release!)
 * code refactored and optimized, 
 (only the UI to display top entry/exit page titles is missing)

Performance improvements
 * Actions Archiving is much more efficient, removed many JOINs and updating algorithm so that we select and parse action names only once per action. 
 * Fixes #1600: datatables now indexed by int, no data migration but code works with both old and new data structure
 * Fixes #1780: new index

Improvements to integration tests
 * never loads the Provider plugin in proxy-piwik.php since reverse ip lookup slows up tests a lot 
 * fixing a test result that were previously incorrect (_withCookieSupport) because a static cache wasn't cleaned after each test 

git-svn-id: http://dev.piwik.org/svn/trunk@3696 59fd770c-687e-43c8-a1e3-f5a4ff64c105