Blender Git Loki

mathtils, convenience attributes added 'row' and 'col', this makes the row/col swap a lot easier to deal with, since
now you can still use column access

previously...
mat[2] = 1, 2, 3

needed to be converted into...
mat[0][2] = 1
mat[1][2] = 2
mat[2][2] = 3

but with column access you can do...
mat.col[2] = 1, 2, 3


Having 'row' attribute is a bit redundant since direct indexing on a matrix uses row but included for completeness.