Clean up some API documentation
add EGL_RENDERABLE_TYPE to OpenGL attributes

This patch adds EGL_RENDERABLE_TYPE=EGL_OPENGL_ES2_BIT to the OpenGL attributes.
The default value for this setting is EGL_OPENGL_ES_BIT and, as we require ES 2.0,
cause some problems on various Android devices (e.g. Amazon Kindle 2.Gen).
wrong variable used which could crash the whole app
re-introduce Cocos2dxHelper.runOnGLThread(Runnable)

It's crucial to execute various tasks synchonized with the rendering loop /
thread, but this ability (runOnGLThread) got removed with the NativeActivity
transitions a few days ago. This patch adds this method back again.

Why can't we just use runOnUiThread()? Because it seems not to be synchronized
properly and can cause broken OpenGL textures or even the whole app to crash.

Isn't there a better way to get into the mainloop? I hope so! But I'm not a
experienced Android developer and this solution is quite simple / the only one
that worked without any problems.
Prevent nullptr access in AssetsManager
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]
Merge pull request #3768 from michaelcontento/android-fix-null-access

[ci skip]wrong variable used which could crash the whole app
Merge pull request #3769 from michaelcontento/android-fix-opengl-config

[ci skip]add EGL_RENDERABLE_TYPE to OpenGL attributes