GPII-566: Revived the contrastEnabled adjuster.
Removed the "default" contrast theme selection.
When contrast is disabled, set default theme programmatically.
Contrast theme panel is conditional to contrastEnabled.
GPII-523: Added model transformation for contrastEnabled.
GPII-573: Corrected the styling bug in ON/OFF switch
under Windows 7 and Mozilla Firefox
GPII-573: Fixed some styling issues with ON/OFF adjusters.
Merge pull request #21 from chrispetsos/GPII-566

GPII-566: Revived the contrastEnabled adjuster. - merging after review from Justin
Merge pull request #22 from chrispetsos/GPII-573

GPII-573: Corrected the styling bug in ON/OFF switch under Windows 7 and Mozilla Firefox. 

Thanks for reviewing this @jobara