attach: add an option to pipe the attachments in

Add the -r option to :attach so that the attachments can be piped in
from a command. Example:

:attach -r image.jpg read-jpeg-from-clipboard.sh

It takes two parameters: the attachment name (to be used in the email
and to get the MIME type from) and the command to execute and read the
output.

Signed-off-by: Vitaly Ovchinnikov <v@postbox.nz>
Acked-by: Robin Jarry <robin@jarry.cc>
Reviewed-by: Koni Marti <koni.marti@gmail.com>

0 files changed, 0 insertions, 0 deletions