Merge branch 'release/0.5.3' into develop
Merge branch 'hotfix/0.5.4' into develop
Fix the usage of XCTAsyncTestCase in Xcode 6 (will be replaced in the future with the build in possibilities)
Add update strategy to relationship descriptions
Append objects to the set of related objects, if the relationship has the strategy append
Set Version to 0.6.0
Merge branch 'release/0.6.0'