Merge pull request #2 from AntonTheDev/master

CSMapper Performance Update
bumped CSMapper
updated source tag
Merge pull request #3 from AntonTheDev/master

Updated Documentation / Added Initializer / Added Array Subtype Parsing
bumped version in podspec
added a way to filter by groups and added the possibility to use json files for mapping
added doc to readme
updated podspec
Changed the CSMappingArraySubTypeKey to CSMappingCollectionSubTypeKey, the mapping value has been changed to collection_subtype for the plist / json mapping, and can now handle NSDictionaries