SCULPT_undo_push_begin no longer takes an explicit
name. Instead it takes a wmOperator pointer and uses
op->type->name for the name. This is necassary for
the redo panel to work and should fix the entire class
of bugs related to misspelled undo push names.
Cases where the calling operator is not registered
may use SCULPT_undo_push_begin_ex if desired; it
takes a name string as before.
3f9299e45d