Blender Git Loki

Feature Request T54106: When scaling keyframes, merge (by-averaging) selected keys
that end up on the same frame

Currently, when scaling keyframes in the Dopesheet, if multiple
selected keyframes end up on the same frame post-scaling, they
would not get removed by the "Automerge" setting that normally
removes duplicates on the same frame.

This commit changes the behaviour so that when multiple selected
keyframes end up on the same frame, instead of keeping all these
around on the same frame (e.g. resulting in a column of keyframes
on different values), we will instead merge them into a single
keyframe (by averaging the values). This should result in a
smoother F-Curve with fewer "stair-steps" that need to be carefully
cleaned out afterwards.

Requested by @hjalti