faster new mail check

[Seth Alves <alves@twitch.cp.domain.net>]

This patch nearly does what i mentioned in my previous message (only
select and fetch in a folder if it has no \Unmarked flag).
Unfortunately, this causes a message count to appear by the folder
only after new mail has arrived.  Still, this improves usability for
me by quite a bit.  Could someone more clued with elisp change this so
nnimap will ignore the \Unmarked flag if a message count has not been
determined yet?

	-seth


*** nnimap.el-dist      Wed Aug 12 12:38:59 1998
--- nnimap.el   Wed Aug 12 13:46:15 1998
***************
*** 546,551 ****
--- 546,552 ----
  ;;; Returns: GROUP HIGHEST LOWEST [ynmxj=]
  (defun nnimap-request-list-mapper (sym)
    (unless (or (member '\\NoSelect (imap-folder-get 'flags (symbol-name sym)))
+             (member '\\Unmarked (imap-folder-get 'flags (symbol-name sym)))
              ;; We ignore groups with spaces (Gnus can't handle them)
              (string-match " " (symbol-name sym)))
      (let ((group (symbol-name sym)) high)