support for DQL identities
move common methods from child class to parent
Add table name to filters
add is [not] null to user defined field rather than hardcoded field(!?)
Merge branch 'KM-507' of github.com:kodify/SimpleCrudBundle into KM-507
fix bug introduced by PR #64 for paging forcibly counting distinct (calculated total could be LESS than actual returned rows)
Merge pull request #66 from kodify/KM-507

KM-507 - support for DQL identities