Issue40 item compare

[codernator]

When info is requested for an equippable item, the info for the corresponding equipped item (if any) is displayed under the info for the requested item. If the requested item is already equipped, then no comparison is made, but the iteminfo_title_equipped string resource is appended to the title.

• It will show the corresponding equipped item -- eg helmet to helmet, boots to boots, etc.
• If you've dual-wielded and you look a shield, it will compare to the weapon in the off-hand.
• If you look at the weapon in your shield hand, it will compare to the weapon in your weapon hand.
• If you look at a ring, it will compare to both equipped rings when appropriate.
• If you look at a weapon, it will compare to items equipped in each hand (weapon/weapon or weapon/shield) as appropriate.