particle designer2.0 support
Fixed compiling-warnings (MSVC2012): C4996(* was declared deprecated), C4305 (* truncation from 'double' to 'float'), C4018 (* signed/unsigned mismatch), C4800(* forcing value to bool 'true' or 'false').
Clean up some API documentation
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into develop
modify particleSystem format erro
revising indent Erro
Merge branch 'develop' of https://github.com/cocos2d/cocos2d-x into develop
Merge pull request #3550 from michaelcontento/fix-assetmanager-delegate-nullptr-access

Prevent nullptr access in AssetsManager
Update AUTHORS [ci skip]
Remove layoutexecutant class
Modify windows project.
Modify layout enum
Merge pull request #3774 from nutty898/optimize_layout

[develop] [GUI] Optimize layout
Adds CHANGELOG and AUTHORS to cocos2d_libs project.

Easier to update those files if they are part of the lib.
And useful for developers as well, specially the changelog
Logs when software decoder is being used

Logs when software decoder is being used in `Image`
Merge pull request #3781 from ricardoquesada/xcode_changelog_authors

[ci skip]Adds CHANGELOG and AUTHORS to cocos2d_libs project.
Merge pull request #3782 from ricardoquesada/software_decoder

[ci skip]Software decoder
Merge pull request #3767 from michaelcontento/android-add-runOnGLThread-back-again

[ci skip]re-introduce Cocos2dxHelper.runOnGLThread(Runnable)
[ci skip]
[ci skip]