Various little changes
Various little changes
Merged
revert-buffer support complete
Set revert-buffer-function in the right place
Corrected a small bug
Added the forgotten (mu4e-main-mode)
Fixed the commented example at the end of the mu4e-main.el file.

Now queuing/unqueuing should work fine in any mu4e mode if one executes
those definitions.
Automatically insert a date field in the new drafts headers.

So that one can see when a draft was composed when browsing the
draft maildir (instead of getting "None" in the Date column). Then one
can sort the drafts by date.
Added a missing ";; New" comment.
Merge pull request #430 from taurgal/master

* mu4e: Add revert-buffer support to the mu4e main buffer