Blender Git Loki

NLA SoC: More UI work + 'Push down' tool

'UI Work'
* Added more drawing code for drawing NLA data
* Made the operators for the 'channel-list' of NLA work. A special version of borderselect for the NLA channel-list (due to the different vertical order) still needs to be coded though.

'Push Down' tool
The active action of each AnimData block, represented by the reddy/orange channel, can be added to the NLA stack as a new action by using the 'snow-flake' icon/button (probably need a special icon for this later). This will add a new NLA track and an NLA strip referencing this action. The AnimData block's 'active action' slot will then be left empty.

(Unfortunately, there still seems to be a bug here, which I'll check on later)