ec4323f95b
Quite a few flags in `Strip.flag` were used only at runtime; they were temporarily set and then cleared thereafter. Move them to `StripRuntime.flag` instead. Most of the moves are trivial renames, with some old versioning code for `SEQ_FLAG_DELETE` deleted. That code fixed a very uncommon edge-case bug in 2.x which doesn't seem worthwhile to keep deprecated code around for. Pull Request: https://projects.blender.org/blender/blender/pulls/142776