LP#1494544 Complete XUL UI for adjustment vs. void options

LP#1494544 Complete XUL UI for adjustment vs. void options

This commit does several things to complete the adjustment UI changes.

1) Adds "Adjust to Zero" to the "Actions" menu.  It was previously only
on the right-click popup.
2) Shows or hides the void/adjustment controls based on permissions.
3) Generates a new force-verified warning if you attempt to void, but
there is also some chance that doing so would be contrary to your
negative balance policy settings.

Signed-off-by: Dan Wells <dbw2@calvin.edu>
Signed-off-by: Jason Stephenson <jstephenson@mvlc.org>