Changelog:
- Add QtAVWidgets module contains widget based renderers, video preview
widget
- QtAV module only depends on QtCore and QtGui
- Improve audio output API
- Simplify deployment on OSX. Deploy sdk from release packages without
build.
- Improve seekable detection
- Fix noise audio if volume increased
- Fix noise and wrong playback speed for wmv videos
- Preview is more accurate
- Do not copy AVPacket but use reference count.
- Faster audio track switch
- Reopen audio output only if audio format changed
- VideoFrame: new API for converting to another format or QImage
- OpenGL VAO, VBO support.
- QML
  * Fix some crashes in QQuickItemRenderer
  * Add FBO item renderer and use the same code path as other opengl
renderers
  * timeout property
- player and QMLPlayer example
  * player: real time preview on progress bar
  * Fast seek and display if seek shortcut is pressed and hold