If the message isn't worth showing immediately, it is not worth
saving!
(Don't save a message unless we get at least a non-null subject and
non-null sender during first pass sync.)
Provide for only showing folders that are subscribed on the server
(IMAP only)
Also:
Change default for Notification behavior to the old way. Make going
to the search for unread messages off by default.
Fix up some hiding of labels, etc. on the incoming server settings.
Check for message suppression in search results.
- Created "controller" and "mail.filter" package
- Moved a lot of classes to new/other packages
- Removed unused classes: NoSuchProviderException, MessageDateComparator
