Fixes to asset manager in the MASTER branch
issue #2050: unsigned int to int
issue #2050: delete max/minGID, fix firstGID bug
issue #2050: use static_cast
closed #2050: Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into bug2050_tilemap_firstgid_bug

Conflicts:
	cocos/2d/CCTMXLayer.cpp
closed #2050: fix js glue code.
fixed #3456
issue #3456 replace jsoncpp to rapidjson.
issue #3456 ios test rapidjson.
Merge branch 'develop' into #3456

Conflicts:
	build/cocos2d_libs.xcodeproj/project.pbxproj
	cocos/editor-support/cocostudio/CCDataReaderHelper.cpp
	cocos/editor-support/cocostudio/CCSGUIReader.cpp
	cocos/editor-support/cocostudio/CCSSceneReader.cpp
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into #3456
upload trigger code.
fixed warning
Test triiger 3.0
fixed #3647  fixes ComAttribute warning.
Merge branch 'develop' into #3457

Conflicts:
	build/cocos2d_samples.xcodeproj/project.pbxproj
	cocos/editor-support/cocostudio/CCSGUIReader.cpp
	cocos/editor-support/cocostudio/CCSGUIReader.h
fixed #3457 remove unused comment.
fixed #4357 failed to build android.
fixed #3457 remove jsoncpp cmakelist.
specialize RenderCommandPool<QuadCommand>