Bump dev version to 2.3.4
[DDC-2224] Rewrite instanceof feature with parameter needle ClassMetadata breaks caching of queries.
[DDC-2224] Adjust ClassMetadata processing
Merge branch 'DDC-2224-2' into 2.3
Fix DDC-2252
Merge branch 'DDC-2252' into 2.3
Added test based on https://github.com/Ocramius/doctrine2/commit/e468ced00bd107f40fd08beca4c7cc5a2492a418
Added constant
[DDC-2346] Reapply changes lost in rebase onto 2.3
Fixed typo in SQLFilter (use statement ClassMetadata)
[DBAL-483] Pass default values to DBAL mapping layer correctly to fix default comparision bug.
[DBAL-483] Add sqlite check again as ALTER TABLE is only supported as of 2.4
Merge branch 'DBAL-483' into 2.3
Fix DDC-2409
Simplify condition of previous commit (5cdc73e)
Merge branch 'DDC-2409' into 2.3
[DDC-1984] Throw exception if passing null into UnitOfWork#lock() - which can happen when EntityManager#find() tries to lock entity that was just deleted by another process.
Merge branch 'DDC-1984' into 2.3
[DDC-2426] Missing length attribute in doctrine-mapping.xsd for <id> tag.
[DDC-2267] Allow EntityManager#flush($entity) to be called on entities scheduled for removal.