from Andrew Hale (trumanblending), with some edits to use these in mathutils.Vector added.
Added Functions:
- dot_vn_vn - Dot product of two arrays
- normalize_vn_vn - Normalize an array and store the result in a second array
- normalize_vn - Normalize an array inplace
Renamed Functions:
Some functions have been renamed to make them consistent with the naming conventions used by fixed length array functions.
- fill_vni to fill_vn_i
- fill_vn to fill_vn_fl