Move functions closely related to rendering images and proxies into
render.c and proxy.c files. render.h and proxy.h are created for
functions used internally.
There should be no functional changes.
Intern definitions are moved to sequencer/intern/sequencer.h
BKE_sequencer.h was also cleaned up a bit to make sure that functions
and structs are in correct category.
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D9259
Main DB and it's structs can point to different address after undoing.
In this case problem was that bmain was not updated. Same fix was
done for scene as well.
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D9240
This is first step of refactoring task T77580.
Next step will be breaking up files into smaller ones.
Reviewed By: sergey, brecht
Differential Revision: https://developer.blender.org/D8492