Continuing on from my previous 'Expandable/Collapsable Action Channel' commit, this commit introduces the ability to show/hide the keyframes in each ipo-curve represented by an Action Channel. When you expand an Action-Channel by clicking on the triangle beside its name, you will now be presented with options to show/hide the ipo-curves represented by the Action-Channel, and/or the Constraint Channels belonging to that Action-Channel. Actual ipo-curves will not be drawn in the Action-Editor, but the keyframes will be shown. Screenshot: * http://wiki.blender.org/index.php/Image:244_ActionEditor_SubTracks_01.png Possibly Coming Soon/Further Work: * 'Protection' options for ipo-curves (currently disabled in code, as all IPO-related tools will need to be made aware of this) * Sliders for IPO-Curve Channels of the active Action-Channel