Rotate about X, Y, and Z (no tests yet though)
Rotation stuff RotateAboutX, RotateAboutY, RotateAboutZ (no tests though)

Rotate added, updated RotateAboutX, RotateAboutY, and RotateAboutZ to
premultiply instead of post. (don't have tests yet though)
Switched Scale and TestScale from post- to pre-multiplication.
clean up

Rearranged Transform to emphasize post-multiplication, removed a couple
functions from Transform to prevent user from thinking
pre-multiplication is supported too, cleaned up/updated some
naming/coding conventions throughout, updated TestTransform by removing
the tests for the removed methods.
Translate and RotateAboutZ updates

Switched Translate from post- to pre-multiply, added 2x2 implementation
for RotateAboutZ, did some style cleanup on TutHelpers, added blank inl
file for Multiply.