the CustomData module from the modifier stack rewrite, but with additions
to make it also usable in edit mode. Some of the datatypes from that
module were move to a DNA header file, they are not saved to file now, but
will be soon.
The only code that wasn't abstracted is the uv collapse / merging code. It
is rather complicated, will look into that in the future.
There should be no user level changes.
Brecht Van Lommel