added scroll event support
More numpification of transforms
Numpify cbook.py
Make backend_driver.py interruptable with Ctl-C
update backend_driver
Change default to clip=False in Normalize.__init__
Numpified collections
Facilitate display of colormaps with ColorbarBase
Wrapped long lines in _cm.py; new import syntax
Numpified transforms.py, fixed bug in invert_vec6