improve color_class usage in the default theme.
improve color_class usage in the default theme.

There is still lots of room for improvements, we should add more color
classes so users could choose more colors (conf_colors to be changed
soon).

NOTE: color_class value will be multiply (ie: tint) the existing part
      value.  This applies for both IMAGES (as expected) and TEXT (I
      did not expect it). IOW: do not define the color in the part,
      just in the color class section.

NOTE-2: if you do not define a color class in your theme, the
      conf_colors dialog will have no clue on what is the default
      color.




SVN revision: 46927

rvandegrift/e,tasn/enlightenment,tasn/enlightenment,FlorentRevest/Enlightenment,rvandegrift/e,rvandegrift/e,FlorentRevest/Enlightenment,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment,FlorentRevest/Enlightenment