User Interface Improvements

Added a button to toggle the visibility of units to make the map easier to see.
Corrected missing unit Corps numbers and the spelling of Thielmann.
Added a button to do a "Pass Analysis" to show you how many units each side has not in a ZoC/ZoI, or waiting to enter the map as reinforcements.
Added a "Detachments Available" button to enable the player to see what detachments they have available at any time, rather than having to wait until the detachment placement phase.