multiview: camera is an Object, not Camera datablock
note: I probably still need to address scene duplication (to link to the
right new camera block) and camera deletion.
multiview: removing "multiview" toggle, instead we now have an option to turn single view on
multiview: pre-ui commit. changes in rna and dna
added "use" flag and "default".
default still needs RNA though, because we need to make sure the others
are not default. OR add a scene.defview to SCENE DNA (and make sure it's
handled well went the view is removed)
multiview: fun commit: adding a new property tabs only for VIEW
This will (likely) not make into the final commit, but I don't care.
It's fun coding weekend ;)
multiview: Render Views icon, and cleanups
note: the inkscape file was manually cleaned, so it may even merge with
updates from trunk. I'm curious to see.