This will avoid double payouts via the website. Payouts will be
requested by users and processed by a cron. If, for whatever reason,
users do add two requests (it is checked if a payout exists) they would
only have one successful payout until their account balance is back up
to a save value to trigger the payout.
This should fix any issues with manual payouts being exploited through
the website. Will require some testing by others to ensure things work
as expected.
