ext/resindvd/: Add support for time based seeking.

ext/resindvd/: Add support for time based seeking.

Original commit message from CVS:
* ext/resindvd/resindvdbin.c:
* ext/resindvd/resindvdsrc.c:
* ext/resindvd/resindvdsrc.h:
* ext/resindvd/rsnaudiomunge.c:
Add support for time based seeking.
Make setting dvd:// reset to the default device.
Make the 'audiomunge' element send any new segment start before
the 'gap filler' buffer it generates, and any segment closes
after.
Fixes: #566957