[Bf-python] BPython bug AngleBetweenVecs

[Jonathan Merritt]

>>Hi, this has caused me grief in the past and I have been using a
>>python version of AngleBetweenVecs.
>>    
>>

Incidentally, this is (IMHO) where we need some regression tests.  I
don't think that a general math function like AngleBetweenVecs (with no
GUI dependencies, etc) should be committed without a decent set of
regression tests that run on it and test for odd cases like finding the
angle between a vector and itself.  Functions like this should be
absolutely rock-solid, watertight, bulletproof, leak-proof, cast iron
pieces of... well you get the idea. :-)

-- 
Jonathan Merritt BE(Mech)/BSc
PhD Student - Equine Biomechanics
The University of Melbourne
Veterinary Clinical Centre, Werribee