Export - Collapse All Sequences by default

[stevefal]

When opening the Export Movies or Animatics dialogue (Mac), the sequence list always initializes fully expanded. With hundreds of thumbnails in that expanded list, it's the least convenient state within which to scroll and find the desired sequence(s). I always have to Collapse All Sequences, at which point finding and checking the desired sequences is a snap.

This suggestion is to initialize the dialogue with the list collapsed, saving a step one must repeat for every export.