[imp] mailbox listing speed-up

[Chuck Hagenbuch]

Quoting "Michael M Slusarz" <slusarz at horde.org>:

> I will probably take a look at this over the next few days and provide
> feedback/comments.  My preference at this point would be to simply
> scrap all of the tree walking code - 50% of IMP_Tree has to be code
> dealing with walking the tree - and just do a simple imap_list or
> imap_lsub call and build the tree with that information.

This all sounds good to me. Can you two please coordinate and make  
sure at least the original patch and discussion end up on  
bugs.horde.org?

Thanks,
-chuck