This commit restores some basic functionality for retiming Grease
Pencil sketches. Some of the functionality that existed before still
hasn't been restored (namely snap/mirror tools as well as copy+paste),
though it should be possible to use this for basic retiming and
sketch-frame management again.
- There's still a lot of work required to get this up to the standard
of the rest of the animation editor code, as some of this code was
originally just hacked in based on the old-style code.
- Work is already required to not have to directly access the main db
global to get the list of Grease Pencil datablocks to show, but that
can come along with pending cleanups of the filtering code.
* Brought back backend for editing keyframes IPO/IPO-Curves. Did some refactoring work here that will still have to be verified when operators using them are added.
* Animation channel filtering code now returns the number of channels filtered (for Action Editor to set totrect of channels - TODO still!)
* View2D - made function to check if mouse is in View2D scrollers an API function
* Renamed keyframe related files. The old names were too clumsy.
* Started porting click-select operators for Action Editor. These don't work currently, as the events are being stolen by the markers. This needs to be fixed ASAP.
* Added new 'Animation' submodule under Editors. This will be used to house all code + features that are used by many different Animation Editors (Action/Dopesheet and IPO) as well as other parts of Blender.
* Added back some of the core code need by the Action/Dopesheet editor, which will also be used by IPO Editor.
* Brought back file for keyframing management code (i.e. keyframing.c), but there's still quite a lot of missing stuff that I'll need to restore, so in the meantime, it's #if 0'd out.
* Moved markers code to this new module (I'm not sure whether SVN will recognise this change, as TortoiseSVN doesn't seem to have any obvious copy/move commands)
