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
Fix DDC-2252
Fix arithmetic priority
adding some more doc and examples for lifecycle event listeners and subscribers
cleanup event subscriber note
Update association-mapping.rst
Merge pull request #637 from choomz/patch-1

Update association-mapping.rst
indexby metadata column
missing new line
Added yml example in ordered-associations.rst

And modified it to be in a configuration-block instead of separate code-block
Merge pull request #641 from bksunday/patch-1

Added yml example in ordered-associations.rst
[DDC-2224] Rewrite instanceof feature with parameter needle ClassMetadata breaks caching of queries.
Fixed typos
Merge pull request #644 from pborreli/typos

Fixed typos
Merge pull request #618 from FabioBatSilva/DDC-2188

[DDC-2188] Fix arithmetic priority
Merge pull request #621 from dbu/event-subscribers

[doc] adding some more doc and examples for lifecycle event listeners and subscribers