Extracted the logic for getting the default email gateway settings
Added a page alert when unband is on but no email gateway exists
Insure we unband via email won't work if disabled

This change should fix #22, particullarly the change made to line 269
of class.ADF.php that fix the if statement, which will prevent leaking
the unband link.

This change also fixes some typos and add an extra step to the sendEmail
function that will abort if unban is not active.