Fixed DDC-1884.
CS fixes.
Merge pull request #741 from doctrine/DDC-1884

Fixed DDC-1884.
Second cache level POC
First round of refactory
Fix factory method name
refactoring region access tests
basically support for many to many collection
Refactoring tests
store cascade collections
refactoring collections store
handle one to many collections storage
tests put entities on persist
test one to many orphan removal
drop support for Region#toArray and Region#count
Configurable cache interface
test DefaultCache
drop cache key api from cache interface
refactoring default cache test
Basic interaction between query and second level cache