Little Text patches:

 - setting color should now work correctly (should fix #289)
 - initialize size (previously crashed on neko)
 - fixes to docs of addStyle()

Previously setting Text.color would set _format.color and also apply colorTinting, thus resulting in the wrong color being displayed.

Minitest: https://github.com/azrafe7/HaxePunk-minitests/tree/master/SimpleTestTextColor