Added a more automated way to create Sent and Trash folders since Cyrus doesn't creat...

Added a more automated way to create Sent and Trash folders since Cyrus doesn't create them during account creation.  Also put in a hack to subscribe you to your INBOX as a work around for the fact that Cyrus doesn't have you subscribed to your INBOX automactically.  This is all working with the $imap_server_type var, and shouldn't affect any other server type.  The options only show up in the folders link if you do not have an INBOX.Sent or a INBOX.Trash.

I need to clean up the code, so don't but it seems to work.

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@403 7612ce4b-ef26-0410-bec9-ea0150e637f0