Commiting partial work on query building for versions
More work on version repository
MAIN QUERY REWRITEN FROM SCRATCH !! Now supports pagination, order by and filters.

Doctrine needed a primary key for Version (it was going crazy during hydratation) so now version has an id, but it's not currently used
Auto-hydratation of related tables seems to work very well, Doctrine seems to decide to join also all inherited tables for Object, I hope this won't be a problem in the future...
Merge branch 'master' of git://github.com/VincentChalnot/SidusBundle