fixed problems with joined inheritance and composite keys

SchemaTool now creates all Id columns not just only the first one.
Insert statement for child entity now contains parameter for additional key columns only once.
inheritance with composite keys

added tests for single table inheritance
Adding EntityManagerDecorator base class as an extension point for EntityManager
Fixed typo in hints. Caused slow loading of eager entities.
Added test based on https://github.com/Ocramius/doctrine2/commit/e468ced00bd107f40fd08beca4c7cc5a2492a418
indexby metadata column
missing new line
Added constant
Merge pull request #611 from stefankleff/fix-eagerloading

Fixed typo in hints. Caused slow loading of eager entities.
[DDC-2407] Fix missing support for UUID and CUSTOM id generators in Exporter
Update coding standards

Removing underscores from property/method names and change use statements to PSR-2
Removed unneeded escape character

Removed backslash
Merge pull request #649 from calumbrodie/patch-1

Update coding standards in change tracking cookbook entry
Fixed typo in SQLFilter (use statement ClassMetadata)
Merge pull request #651 from EuKov/patch-1

Fixed typo in SQLFilter (use statement ClassMetadata)
Fixed entities path

In the tutorial, the user is told to create a new file in the '/src' folder, and the 'entities' folder is never referenced. Updating the SQLite schema according to the tutorial fails with the 'No Metadata Classes to process.' message. Changing the folder to '/src' fixes this, ostensibly.
Merge pull request #652 from dannykopping/patch-1

Fixed entities path
Fix DDC-2415
Merge pull request #653 from FabioBatSilva/DDC-2415

[DDC-2415] Fix CustomIdGenerator inheritance
Fix DDC-2409