bitaccess: EXTREMELY URGENT: Missing control of bitcoin amount when selling bitcoin allows a user to withdraw any amount of money, unrestricted.

On cash.bitaccess.co, there was one edge case where user input were not being validated correctly. Thanks to @cablej for reporting the bug in ethical manner and his helpful comments during the fix period. On cash.bitaccess.co, the endpoint for selling bitcoin did not verify the posted amounts of...