Refactor RCTUIManager

Summary:
Moved the view creation & property binding logic out of RCTUIManager into a separate RCTComponentData class - this follows the pattern used with the bridge.

I've also updated the property  binding to use pre-allocated blocks for setting the values, which is more efficient than the previous system that re-contructed the selectors each time it was called. This should improve view update performance significantly.

React/Base/RCTBridgeModule.h

@@ -94,7 +94,7 @@ extern dispatch_queue_t RCTJSThread;
 #define RCT_EXPORT_MODULE(js_name) \
   RCT_EXTERN void RCTRegisterModule(Class); \
   + (NSString *)moduleName { return @#js_name; } \
-  + (void)load { RCTRegisterModule([self class]); }
+  + (void)load { RCTRegisterModule(self); }
 
 /**
  * Wrap the parameter line of your method implementation with this macro to