remove strtok_r() from video_query_info()

for minGW compatibility
dedicated namespace for video-utils

conflicting symbol prophylaxis
advance track's play-position even if processing is locked

fixes
  * http://tracker.ardour.org/view.php?id=5628
  * http://tracker.ardour.org/view.php?id=5561
make master-meter in toolbar optional
fix no-roll LTC encoder, honor locates when transport is stopped
Timecode: fix subframe rounding

if sub-frames are used, frames are rounded up for the later half of
a sub-frame.  e.g. @48KSPS, 25fps, 100 subframes per frame
audio-samples >=1910 already yield 00:00:00:01
vtl: import audio at video-offset, forget offset on "Remove Video"
fix rounding issue when dragging video with fractional fps
fix meter-background highlight when peaking. (> vs >=)