Cosmetics: Use the IID_PPV_ARGS macro when possible.
Improve the reliability of the [DXVA] indicator in the status bar.

Sometimes the indicator wasn't shown while hardware acceleration was used.

This commit fixes #3518.
Get the DXVA status once and for all when opening the file.

No need to check it every time the status bar is updated.
Support for multiple programs in one IFO file.

WIP