[crossfire] Call for testing: updated banks have been committed!

[Kevin Zheng]

Hi there,

A number of overhauls in the banking code have been committed between
r18853 and r18875. Changes with this overhaul include:

 - Lots of cleanup and commenting
 - All commands are implemented in their own functions
 - Unified functions to get coin name/value
 - Balance is given in most valuable coin by default
 - Decimal points are used if necessary on big coins
 - Closing the bank is now REQUIRED with bank.close()
 - ATMs are (temporarily) disabled for money safety
 - Bank fails gracefully if checking is broken

Since big changes can introduce big bugs, I'd like to ask others to
update their maps and try out the new bank. I've made every effort to
ensure that the bank is backwards-compatible and doesn't steal your
money, but strange things do happen. Questions, comments, bug reports,
and hate mail are welcome.

Thanks,
Kevin Zheng