Nice IMAP checkins
Mozilla sometimes doesn't display Sent Items folder with correct headers
This fixes the icons for sent/drafts/templates for imap servers that have their
special folders under the INBOX.
And also some IMAP code cleanup:
- Remove unused nsIMsgFolder methods.
- use XPIDL for nsImapMiscellaneousSink and nsImapExtensionSink
Big Thanx to David Bienvenu, who did a great job on the IMAP code!
Remember that you're always more than welcome to help fix more IMAP bugs. To get started read this document.