Imap-tools

* Fixed: MailBoxFolderManager.list double quotes bug

* Fixed: MailBoxFolderManager.list parse bug

* Moved: SortCriteria to consts
* Added: \_\_str\_\_ to MailMessage
* Added: docs info

* [Breaking] Changed: "bulk" argument at BaseMailBox.fetch now can accept int values >=2 - for control bulk size
* Added "sort" argument to BaseMailBox.fetch and BaseMailBox.uids - for sort on server. Use SortCriteria constants
* Renamed: utf7_encode and utf7_decode from imap_utf7.py (was encode and decode)

* Fixed: MailAttachment.filename parse non-ascii filename

* [Breaking] MailMessage.html replacing charset to utf-8 in html meta for consistency
* Added utils.replace_html_ct_charset