rearrange README usage chapter
Merge branch 'bjoska-rake_addition' Closes #4

Merge bjoska changes, with README rearrange.
BlinkStick::Version addition

This was commented earlier, but has now been corrected.
BlinkStick and ColorHandler

Extraction of methods relating to color change etc.

Rework of the code in BlinkStick in general. Removal of class variables
in favor of constants and a class instance variable.

Plus some general refactoring of methods.
Color, Parse and Hex corrections