* Removed sqimap_mailbox_close() function -- automatically expunges mailbox

* Removed sqimap_mailbox_close() function -- automatically expunges mailbox
    when it closes.  Someone suggested that we use this, and I hadn't
    researched its functionality enough before implementing
* Made the $auto_expunge variable actually do something.

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@919 7612ce4b-ef26-0410-bec9-ea0150e637f0