This patch contains changes from D10321
This patch contains still lot of code that needs to be investigated. It should work with code commented out as is, and suspicion is that this code is not needed.
Reduce complexity of sequencer transform code by removing recursivity.
This is possible by treating meta strips (mostly) as any other strip and
containing all transform code within `SEQ_` functions.
Unfortunately internally meta strips still require special treatment,
but all complexity from code all over transform code seems to be
possible to contain within one function.
Functional change:
Previously adjusting handle of single omage strip moved animation.
Now animation is not moved, which is behavior for all other strips.