Do not update resume information and do not log statistics when a

Do not update resume information and do not log statistics when a
track is interrupted within the first 15 seconds.

Regard a rewind to 0:00 as a track restart (updating resume position /
playback statistics before the rewind and starting the 15 s delay).

This allows skipping forward across an unplayed track without changing
its resume offset.  Also, it is possible to skip backward to the
previous track after rewinding to the current track to 0:00 (pressing
Left twice) without losing the current track's resume position.

Initially contributed by Dave Slusher

Caveats:

* Works only for SWCODEC
* Skipping forward without altering the resume position does not work
  when skip to outro has been turned on.
* The 15-second window in which the resume offset will not be updated
  should start at the initial resume position, not at 0:00.  This
  would allow skipping over partially played tracks without altering
  the resume position.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@29250 a1c6a512-1295-4272-9138-f99709370657