Weight Builder, Xform Builder: added utility python funcs (bbox fit, etc)
ENHANCED: Bias Deformer qL SOP (could be used as template)
- a bit better Twist qL SOP, too
FIXED: Sweep qL SOP (hopefully)
Merged work: deformer base "architecture"-related
- added common utility functions to xformbuilder and weight_builder
- Bias Deformer qL SOP is now the intended example to follow
  - parameter names, UI behaviour, guides, etc.
- (misc other stuff)