VSFilter/ISR: Fix override placement not being applied even if enabled.

ISR: Fix subtitle default style being lost after changing default style in settings.

Fixes #34.
VSFilter: Pass through dwTypeSpecificFlags and dwInterlaceFlags.

This fixes interlaced videos.

Fixes #2671
Repaint video frame when toggling statistic.
Hide unneeded line in statistic when VSync is enabled.
RTS: Fix outline size when using default style for ASS subtitles.

Fixes #3701
RTS: Add some rounding to ensure higher precision.
RTS: Change work-around for m_dstScreenSize to preserve proper subtitle
positioning and preserve subtitle font size for default style along
different subtitle files.

Fixes #1574
RTS: Don't remove subtitles effect when default style is applied.

"Default Style" option is to apply default style for subtitles and not
actually completely break them.

Fixes #4171
SubPic queue: Clear queue only when it's needed.

Time can decrease even within the same video frame and
it make no sense to purge whole queue, if we still can reuse buffered
subpic.
Don't set subtitle again when manipulating style.

Fixes #2244
Use dynamic_cast instead of evil C style casting.
ISR: Disable "Default Style" menu item when not applicable.