Deletes root/version.json, it was added by mistake.
Adds ccs-res submodule for storing resources of CocoStudio
cocosgui -> cocosui, update Xcode project.
tab -> 4spaces for TestCpp/Classes/AppDelegate.cpp
Updates TestJavascript.xcodeproj
Ignore external/version.json
libExtension.vcxproj doesn't depend on libBox2D
Merge pull request #6624 from dumganhar/v2

[v2] Adds 'ccs-res' submodule for storing CocoStudio resources, use the same version as v3 branch