Blender Git Loki

Fix T81533: NLA Properly Draw FModifiers

When NLA strips weren't time-aligned with the underlying action, then
fcurve modifiers would not be drawn anchored to the strip. Fmodifiers
were evaluating properly, they just weren't drawn with the proper
offset and scale.

To fix it in this specific case, I've chosen to undo the keyframe
remapping then remap the draw-evaluation-time from scene time to
fcurve time. Afterward, I redo the keyframe remapping so the controls
are properly drawn.

The Envelope fmodifier has special drawing code which was fixed too. In
this case, no mapping at all was happening. The solution was similar,
to remap the envelope control points from fcurve time to scene time.