Changed the default behaviour to use Marc's experimental cpde... note this

Changed the default behaviour to use Marc's experimental cpde... note this
is devel, and would be great to get some field testing (courier/uw would be
great)... it seems to fix the folder display issues with Exchange IMAP where
folders where appearing in the wrong order.

Fixed an E_ALL error, and pulled the $imapConnection into the function,
Marc are you running with E_ALL?  The code caused an immediate error as it
couldn't connect to the IMAP server, causing a nice folder order to appear:
  (http://nuts.netdork.net/bad_folders.jpg)

Also fixed a couple of cases of "Editor Envy" and replaced \t with "    "
(hence the massive diff).

Also fixed the code so that the "Trash" is now selectable, and moved the
 (purge)
link back to after the mailbox name.

git-svn-id: https://svn.code.sf.net/p/squirrelmail/code/trunk/squirrelmail@5029 7612ce4b-ef26-0410-bec9-ea0150e637f0