The crash fix simply avoids using a negative index. The label change just fleshes out the use of ButtonType on the UndoButton (used for both un/redo).
Merge remote-tracking branch 'remotes/billlutton/fixUndoRedo'
Squashed commit of James' work - context menu items:

commit d413a5afbcc34276d916e6b03df881b3d2086beb
Author: James Bolding <bolwire@cableone.net>
Date:   Mon Nov 25 23:59:21 2013 -0600

    Added two options to context menu,
    First aligns the effects start and end times with one click.
    Second matches the duration of all selected elements without change to start times.
Fix formatting error in mark generation.
Merge remote-tracking branch 'remotes/sall/master'
Removed local files that were removed from resources Resources/arrow_loop.png and Resources/control_play_red.png
3.0.10 release prep.
Interpolate HSV colors properly -- wrap around the 360 degree point on the color wheel, rather than doing all transitions within the 0 -> 360 bound.

(note: I was pretty damn sleepy when writing this, so I suspect it's inefficient. Feel free to optimize it if there's problems with it.)
Fixed spacebar not stopping sequence when using loop, it would just restart the loop.
Updated Sequencer
Merge remote-tracking branch 'remotes/sall/master'