[PATCH] Syncing gmail labels for gmail accounts

[Dima Pasechnik]

Another question about this patch: how easy it to change it to use
X-Label rather than X-Keywords?
(There are minor differences in format between them).

X-Label header is supported by mutt (there are also patches to edit
them), so if for some reason one cannot use mu4e there is still a way
to deal with these things.

I also noticed that one still gets empty subdirectories corresponding
to the gmail tags in the Maildir with your patch. Is it intentional?

Thanks,
Dmitrii