Machinery money changes

Created by: ComicIronic

A lot of code standardising for the way machines handle trying to take money from a user. All machines can now be set to connect to the accounts database in initialize(). reconnect_database(), connect_account(), and scan_card() have all been moved to the machine level. Merch computer now reads your equipped ID, not your mind account. Fixes #2854 (closed). All machines getting your ID using get_id_card() now check all your slots, with hands being prioritised over the ID slot. Removed a pointless human-only proc that was causing befuddlement.