Fixes for #293.
Refactored association handling.
Merge branch 'trunk' of github.com:impetus-opensource/Kundera into trunk

Conflicts:
	kundera-core/src/main/java/com/impetus/kundera/PersistenceUtilHelper.java
	kundera-core/src/main/java/com/impetus/kundera/persistence/AbstractEntityReader.java
	kundera-core/src/main/java/com/impetus/kundera/persistence/AssociationBuilder.java
	kundera-tests/src/test/java/com/impetus/kundera/tests/crossdatastore/useraddress/MTMBiAssociationTest.java
Fixes for #293
Merge branch 'trunk' of github.com:impetus-opensource/Kundera into trunk