Fix "On top while playing video" after 6cbe725c8b755854d37a6f46cb603e9f48116655.

The "on top" flag was lost when exiting the full screen mode.
Make "Sharpen Complex 2" shader compatible with Pixel Shader 2.0.
Add the ability to close a media instead of pausing/stopping at the EOF.
Audio Mixer: Faster volume regain.

This commit fixes #1936.