Theme engine: simplify color definitions and interface
Custom UCs: tie coloring into updated theme engine
Radio button and check box UC: remove caption autosize

While Unicode support isn't slated for 6.4's release, there are a few
parts I want to have in place before 6.4 releases, to make the best use
of the large-scale debugging that accompanies a beta release.

One of those changes is removing the default "autosize" ability of the
radio button and checkbox controls.  RTL languages make this approach
problematic, and because control width is deeply tied into the
translation engine (so that over-long captions are automatically
down-sized), I want to modify this behavior prior to 6.4's release.

(This is a huge commit because all instances of these UCs have been
manually resized to account for the change.)
Radio button and check box UC: fix click and hover behavior

Now that the controls aren't autosized, they will almost always be
larger than their relevant clickable area (e.g. the box/button and
caption).

As such, clickable area is now determined programmatically, instead of
using the full size of the control.  Note that as part of this,
auto-shrinking of too-large translated captions is broken.  Fixing it is
on my to-do list.

Also, this commit is once again huge because VB lost a bunch of my
property changes from the previous commit.  Aaaarrrrgggghhhh