New Stuff:
* When in PoseMode, the Ctrl-G hotkey now presents a menu with options for manipulating Bone Groups. There are options to add/remove all selected bones from a certain group.
TODO - add appropriate entries to menus
Bugfixes:
* Renaming Bone-Groups in the buttons panel could cause segfaults or memory corruption. Wrong maximum-length for button used here (it's far too easy to miss).
* In the Action Editor, (re)grouping channels didn't take into account whether a group was expanded or not. This meant that selected channels from inside a collapsed group got added to the new group too.
d23bcd8b7f