PATCH: IMAP flag handling and new mail notification

["M . Thielker" <balsa t-data com>]

Hi,

 here's one that _really_ ought to go into CVS.

Fixes:
- Message flags "Seen", "Answered" and "Flagged" are lost when
  a message is moved into an IMAP folder
- Messages freshly moved into IMAP folders, but never opened from
  there will appear as new messages the next time Balsa starts
- New Mail sound not working properly

Provides:
- Optional dialog box to show that new mail has arrived
- Suppression of the progress dialog when mail is checked in
  the background
- Better control over IMAP mail checking (All, INBOX only, None)

Supersedes:
- balsa-checkprefs*

Requires:
- 1.1.6 CVS or 1.1.7 source tree

All other patches I make will be against a version with this patch applied.

Melanie

balsa-imapflags.patch