Added newInstance and newIsntaceWithContext for object creation.
Allow for In-Memory store types and use within logic Unit Tests.
Merge remote-tracking branch 'upstream/master'
objectForClass -> managedObjectOfClass
Merge pull request #22 from chillpop/master

Convenience factory methods for managed objects and ability to use an in-memory store
Merge branch 'master' of github.com:vokalinteractive/CoreDataManager-iOS