Fix seeking when Cues are populated with alternating CuePoints for each track.
Fix seeking when Cues are populated with alternating CuePoints for each track.

Previously, nestegg would select the CuePoint with the closest CueTime to
the target, then verify the seeked track was present in the
CueTrackPositions.  This has now been changed so that nestegg selects the
closest CueTime that has the seeked track present in the CueTrackPositions.

bit/nestegg,bit/nestegg,kinetiknz/nestegg,fallaciousreasoning/nestegg,SingingTree/nestegg,SingingTree/nestegg,kinetiknz/nestegg,fallaciousreasoning/nestegg,SingingTree/nestegg,kinetiknz/nestegg