fixed #2247: Using functions instead of macros to speeding up building for JSB projects.

JS_NEW_PROXY --> jsb_new_proxy
JS_GET_PROXY --> jsb_get_native_proxy
JS_GET_NATIVE_PROXY --> jsb_get_js_proxy
JS_REMOVE_PROXY --> JS_REMOVE_PROXY

Since the implementation of JS_XXX macros are using UTHASH which is also implemented by marcos totally,
it will expand `jsb_cocos2dx_auto.cpp` to a very huge state when compiling which makes the compilation very slow.
On android, just building *jsb_cocos2dx_auto.cpp* and *jsb_cocos2dx_extension_auto.cpp* will take *5 minutes*.
After these changes, it takes only *2 minutes*, it means that, we can save about more than half time than before.

The changes of Cocos2d-x is here (https://github.com/cocos2d/cocos2d-x/pull/2725).