Spidermonkey should be built in RELEASE mode for all platforms.

Relevant issues were created at 
http://www.cocos2d-x.org/issues/3853
http://www.cocos2d-x.org/issues/3857

### REASON WHY WE HAVE TO USE RELEASE VERSION LIBRARY: ###
We used fat library for iOS, it contains `i386`, `armv7`, `armv7s` architecture. But we use the same header files.
The head file of Spidermonkey contains DEBUG macro in some methods or some classes. It may lead to weird crash.

### HOW TO FIX: ###
Undefine all `DEBUG` marcos in Project Settings.
Build all libraries in `RELEASE` mode.

**If you wish to debug Spidermonkey, you have to know how to build debug version of SpiderMonkey and how to set DEBUG macro in Project Setting!**

### BUT DON'T DEFINE `DEBUG` macro IN OUR PROJECTS ###

Cocos2d-x is using `COCOS2D_DEBUG` for debugging.