T2D style 'Stock colors'

This commit implements stock colors as they are implemented in T2D.
It allows for using predefined stock colors e.g.:
``` %object.color = "OrangeRed"; ```
Instead of
``` %object.color = "255 69 0"; ```
Initialize StockColors
This commit makes sure the StockColors are initialized and destroyed, using
the module system.
Merge pull request #613 from lukaspj/T2DColors

T2D style 'Stock colors'