Blender Git Loki

Revision of NLA stride option.

Previously, using the "Stride Bone" tried to get that Bone motionless on
the path by correcting the internal time of the Action. This however caused
too many problems, especially with irregular walks.

The new system also tries to keep the Stride Bone motionless, but this by
moving the entire armature, and not changing the timing of the Action.
Give much nicer results. :)

To make editing Strides easier, I've added a new option in the NLA
panel to disable the path. This way you can quickly switch to editing the
action itself (keying the stride bone) and viewing the result.