Remove RACPropertySubject
Refactor RACBinding as endpoints with signals/subscribers
RACObservablePropertySubject -> RACKVOBinding
Update -rac_setArgument:atIndex: to support arbitrary types.
Update -rac_argumentAtIndex: to support arbitrary types.
Update -rac_returnValue: to support arbitrary types.
Remove reference to type limitations.
Added back char pointer lifting tests.
Add back string support to RACTypeParsing.
Updated change log.
Revert "Updated change log."

This reverts commit 50052771057c3dd8617b7caf0831b2a4a2e562ea.
Removed section about char * lifting from change log.
Add vertical whitespace.
Switch the dynamically allocated buffers with local variables.
Add back test for lifting const char *.
Add test for structs.
Increase the size of the test struct to make sure it doesn't just work for small structs.
Move endpoints' logic into RACBinding directly
Refactor NSObject+RACAppKitBindings
Add back notes pointing out arrays and unions are not supported.