Update RKMapping.h

importing foundation to get rid of swift complier error
extended RKObjectMappingMatcher capabilities with a RKKeyPathClassObjectMappingMatcher class
removed unnecessary check
Merge pull request #2002 from valeriomazzeo/RKKeyPathClassObjectMappingMatcher

extended RKObjectMappingMatcher capabilities with a RKKeyPathClassObject...
Merge branch 'patch-1' of https://github.com/Jian130/RestKit into Jian130-patch-1
Merge branch 'Jian130-patch-1' into development
Allow for the Testing and CoreData subspecs without the Search subspec
Merge pull request #2007 from RestKit/testing-with-core-data-without-search

Allow for the Testing and CoreData subspecs without the Search subspec
Ignored undeclared selector warning for search indexer RKTestFactory code
Bump version to v0.23.3
Merge branch 'release/0.23.3' into development
Merge branch 'development' of https://github.com/RestKit/RestKit into iOS8_beta_workaround