CHANGES DONE TO LIBRARIES
=========================
- edited zend_log and changed attr to protected
- fixed bug fwrite in zend_log stream writer
- fixed PEAR so that it works under PHP5 with STRICT MODE enabled


# Documentation
  - Document the Piwik architecture: 
   API concept, 
   Plugins concept, 
   Logging engine,
   Archiving process, 
   Reporting process, 
   MVC model, 
   DataTable concept

   
test that archive always is OFF in prod
$GLOBALS['DEBUGPIWIK'] is false;

optimize getdateStart / getdateEnd in *Period