Improve the OSD when using VMR-9 (windowed) renderer.
Fix: Play > Subtitles menu sometimes showed the wrong track as selected.

If the subtitles track was changed at the splitter level the Play >
Subtitles menu wasn't reflecting the change correctly.

The handling of the subtitles tracks have been rewritten to avoid storing the track number.
Cosmetics: build.bat and gccbuild.bat error handling improvements.
Use /Silent switch for gccbuild.bat when building through MSVC to avoid unneeded pause message
Add /Nocolors switch to disable colors in batch files output.
Disable colors also for /Silent switch.