Make the column for the voucher prefix wider, since we're putting 'COINPAY-' in the voucher code - it's longer than previous prefixes.
Store email addresses in voucher_requests table so we can remember who we sent the voucher to.
Make $email available to all pages.  Require users to be logged in to use 'send' and 'receive' pages.
Add code to show when bitcoins have been emailed.
send page has tabs now too.
Show emailed bitcoins on statement.
Code for emailing bitcoins.
Turn on vouchers, and change their prefix to 'COINPAY'.
Started with 'withdraw.php' and changed a lot.  It's now tabbed, and includes the ability to send bitcoins via email.