* Error handling for colour value entry.
* Implement cache to texture for Allegro.
  - Undocumented optimisation that allows controls to have their contents cached in the texture. This is preferable for controls that are CPU intensive to draw, like the colour selector.
* Rename methods to be less ambiguous: "Set" expects and arg.
* Use the RGB <--> HSV colour-space conversion functions from Allegro. Less type conversion and easier to read.
* Readme updated for recent changes.
Merge branch 'gwork' of https://github.com/billyquith/GWEN into gwork

Fix Conflicts:
	README.md