Fixed bug where tableMaps were not cached.
#478 - Performance increase from 16,252,928bytes/3.284s =>  12,058,624bytes/2.170s
Removed slow in_array and replaced it with isset for `modifiedColumns`.
#478 - Performance increase 100ms
Removed slow call_user_func and replaced it direct call.
#478 - Performance increase 50+ms
Merge pull request #479 from marcj/perf

Perf
Fixed memory leak in Collection class with a new implementation.

#478 - memory consumption optimized from 12,377,160 bytes to 6,053,976.
Merge pull request #482 from marcj/perf2

Fixed memory leak in Collection class with a new implementation.
First version of bugfix for #473.

and some other stuff.
Even more fixes.
cleanup
Implemented correct addCrossFKCount
Added more tests for m2m and one2many objects. Fixed small issues with that.
add compatible doCount and doSelect methods from query_cache behavior
with ModelCriteria class

return DataFetcherInterface instance for doCount and doSelect methods in
query_cache behavior
Merge pull request #484 from lunika/master

fix query_cache behavior compatibility with Criteria and ModelCriteria
Fixed notice
Merge pull request #494 from marcj/patch-1

Fixed notice
Tables with no primary keys confused code generators
must test if setIgnoreCase exists on each criterion
fix failing tests in ArrayToPhpConverterTest
Merge pull request #506 from csanquer/master

fix failing tests in ArrayToPhpConverterTest
Added hhvm to travis config