* add support for org-mode links to messages/queries

- org-mu4e.el: add "mu4e:"-link type and handlers to org-mode
  - Makefile.am: add org-mu4e.el to package
  - mu4e-hdrs.el: register handler functions for server data *outside* header
    mode, so they can be used independently (and we can link to messages even
    when mu4e is not active already)
  - mu4e-view.el, mu-server.1, mu-proc.el, mu-cmd-server.c: support viewing
    messages by msgid (rather than only by docid); document it

man/mu-server.1

@@ -1,8 +1,8 @@
-.TH MU-SERVER 1 "December 2011" "User Manuals"
+.TH MU-SERVER 1 "January 2012" "User Manuals"
 
 .SH NAME
 
-mu server \- the mu backend for the mm e-mail cleint
+mu server \- the mu backend for the mu4e e-mail cleint
 
 .SH DESCRIPTION
 
@@ -131,7 +131,7 @@ Using the \fBview\fR command, we can all information (including the body) of a
 particular e-mail message.
 
 .nf
--> view <docid>
+-> view <docid-or-msgid>
 <- (:view <s-exp>)
 .fi