Blender Git Loki

More fixes thanks to irc testing;

- On exit editmode and after deleting bones, a pointer in PoseChannels
was not set NULL correctly, causing potential crashes.
- Action Window: select on 'ipo key' (little icon) didn't select/deselect
the associated bone (old bug!)
- After unlinking an Action, the blue color in bones was not cleared

Also:

- Improved selection in editmode, doing it in 2 stages. Makes it a lot more
accurate.