Suspend option button focus rect rendering for now

I hate doing this (especially with the accessibility implications), but
until I can sort out why enter/exit focus events fire sporadically, it's
even MORE confusing to leave the control in its current state (where the
focus rect can appear out of nowhere).
Subclass all picture boxes so that contained controls will render transparently
Rearrange command bar button layout

It really bothers me to have the "save preset" button on the *left* of
the preset combo box.  While this lacks the symmetry of the old
arrangement, I find it much more intuitive.
Make all command bars have TabStop = 0

This allows me to remove the .Default property from the OK button, which
in turn will allow me to automatically save the current preset when
ENTER is pressed while the combo box has focus.  Yay!

Also, the command bar should be the default focus recipient anyway.