Add debug/debug_raw example options to advanced imap config
[mms] Move folder disabling configuration into backends.php.
[mms] Move special mailboxes autocreation configuration into backends.php.
[mms] Move fixed mailbox configuration into backends.php.
Fixed for purposes of dynamic view also includes ACL restrictions
Imap_Client optimizes out empty arrays, so need to do explicit checks at runtime
Add IMP_Mailbox constants linked to the name of the special mailbox prefs
[mms] Allow default special mailbox names to be overriden by a backend.