This is a proposed fix for #128:
* Mark auto_payout running via DB setting, unlock when done
* Just before actually sending money, check for running cron
Please refer to the ticket for details
* Check for min/max values set for auto payouts
* Display error messages to the user
* Sanitize values just in case we fall through the validation
* Updated template and class
* New configuration option added! Update your local configs!
Fixes#108