Fix issue in OECF of "ALEXA Wide Gamut" colourspace model.

Reference #149.
Refactor "ACES RGB Proxy *" colourspace models OECF.

Reference #149.
Improve "C-Log *" colourspace models inverse OECF precision.

Reference #149.
Add unit tests for "RGB" colourspace models OECF and transformation matrices.

Reference #148, #149.
Merge branch 'feature/v0.3.3' into develop