Update _bPlaying on CCActionObject.

The method CCActionObject::isPlaying() return the state of the member var _bPlaying,
which is initially declared false and never updated. The change updates this variable
across the play, pause, stop and end states of the action.
SceneReader sets contentSize by canvasSize.

We could not get the canvas size of the scene which created on CocosStudio.

Thanks to this commit, we can get scene's canvas size by Node::getContentSize()

```cpp
auto scene = cocos2d::cocostudio::SceneReader::getInstance()->createNodeWithSceneFile("Scene.json");
int width = scene->getContentSize().width;
int height = scene->getContentSize().height;
cocos2d::log("canvasSize = %d, %d", width, height);
```
Scale9Sprite capInsets set fix
added  LuaStack::loadChunksFromZIP()
call detach method on thread exit
Fixed LabelAtlas opacity do not change when setting parent node's opacity
modified project files and make files
fix warns and memory leak
Add CameraTest、OBBTest and related lua bindings
Merge branch 'v3' of https://github.com/cocos2d/cocos2d-x into v3_3D
Merge branch 'v3' into v3_fixGLProgramCrash
fix button title only content size issue
Fixed FileUtils::removeFile doesn't work on iOS
fix cocostudio include path
fixed compile error
fix compile error for macro redefinition
remove texture unit 4-7, only 0 -3 is reserved
Merge pull request #7979 from giginet/scene-reader-canvas-size

SceneReader sets contentSize by canvasSize.
Merge branch 'v3' into v3_fixGLProgramCrash
Merge pull request #8610 from andyque/fixCocostudioIncludePath

fix cocostudio include path