PIVOT-925: Fix Expander's title bar color, which is only effective for the first
time the control is expanded/contracted after being set.

I added a field to store the color and changed the method that sets the color
during expansion/contraction to just set the label color from either the saved
color or the inactive color depending on the state.

This is a cross of revision 1536833 from branches/2.0.x to trunk.


git-svn-id: https://svn.apache.org/repos/asf/pivot/trunk@1579081 13f79535-47bb-0310-9956-ffa450edef68