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
entity generator - ignore trait properties and methods
only use already existing reflections
Revert "only use already existing reflections"

This reverts commit bb5bdcf0f4ccd6fc83692490ec70a697c90573fb.
only check for traits when class exists
check if ReflectionClass::getTraits() method exists
fixed code duplication issue
added unit test
indexby metadata column
missing new line
Add hidden field ordering for postgresql

In postgresql environment, when some hidden fields are used in orderBy clause,
they're not property added because $rsm->scalarMappings don't have information about them.
Revert "Add hidden field ordering for postgresql"

This reverts commit 3e8796f78188e193aac7386b38b7e17da3df5718.
Add test for postgresql hidden scalar sorting
Fixed postgresql hidden scalar sort
minor fixes
moved test entities from sandbox
skip test if php 5.3
[DDC-2407] Fix missing support for UUID and CUSTOM id generators in Exporter