support for changing the actionbar text color

The title says all

Other notes:
* This only support setting the color of title (sets `titleTextStyle` in the styles)
* The ABS support may not be correct, as the code is based on the answer at http://stackoverflow.com/a/10357340/1523910
* The Transparent and the Solid title colors are same.
This parent style is invalid - should be TextAppearance.Holo.Widget.ActionBar.Title