Blender Git Loki

Nla Refactor: Split animsys_evaluate_nla()

No intended functional changes.

Refactors animsys_evaluate_nla() into 2 versions:
animsys_evaluate_nla_for_keyframing(), animsys_evaluate_nla_for_flush()
to make it clear what data is being calculated and why.

Dummy strip creation has been refactored to two separate functions,
animsys_create_tweak_strip() and animsys_create_action_track_strip().
Both are evaluated differently from other strips and eachother. There's
no need to interweave them. A future patch D8296, generally requires
both strips.

___

XXX anim_sys.c) nlatrack_find_tweaked() is a temporary work around.
If anyone has any insight into this problem, help is appreciated.

Reviewed by: sybren

Differential Revision: https://developer.blender.org/D9696