Merge branch 'master' of https://github.com/cocos2d/cocos2d-x
fixed isFileExist to use full path
fix armature draw
updated readme with note to clone the repo and not download the zip version
Merge pull request #3858 from MSOpenTech/winrt-readme-fix

[ci skip]Winrt readme fix
update render
Merge branch 'render' of https://github.com/2youyouo2/cocos2d-x into render

Conflicts:
	extensions/CocoStudio/Armature/utils/CCSpriteFrameCacheHelper.cpp
	extensions/CocoStudio/Armature/utils/CCSpriteFrameCacheHelper.h
change CCArmature::boundingBox to apply CCNode::boundingBox
Merge pull request #3851 from MSOpenTech/winrt-fileutils-fix

[ci skip]Winrt fileutils fix
load system Chinese font on winrt since MarkerFelt font is missing Chinese characters
support for precompiled shaders on winrt/wp8
added sha1 algorithm since it is missing in WP8 SDK
added winrt precompiled shaders
removed precompiled shader code
added support for precompiled shaders
added precompiled shader support for winrt/wp8
removed old precompiled shaders
removed old WP8 precompiled shaders
added CCPreompiledShaders.h for winrt and wp8
adding loading of precompiled shader programs