bug#11212: 24.0.95; mailcap-mime-extensions: Add opendocument formats

[Jambunathan K <kjambunathan@gmail.com>]

Glenn Morris <rgm@gnu.org> writes:

>> Please include OpenDocument extensions to `mailcap-mime-extensions'.
>
> On non MS systems, there is no need, because there are system files
> such as /etc/mime.types that contain this information, and
> mailcap-parse-mimetypes combines these with mailcap-mime-extensions.

My thoughts (See C-h f mailcap-parse-mimetypes)

My machine falls under `mailcap-poor-system-types'.  To use the right
mimetype for outgoing attachements, I need to do one of the following:

1. Set the environment "MIMETYPES" and point in to the mimetype file
2. Create one of the following files "~/mime.typ", "~/etc/mime.typ" 
   and start populating it. (Why do these file names have a typo?)
3. Push an entry via elisp in to `mailcap-mime-extensions'.[2]

Unfortunately info lookup throws up nothing when I search for 1, 2 or 3.

The above options are user-facing and need to be captured in the manual.
It is also desirable that one of the above entries be exposed via custom
group mailcap or mime.

ps: Emacswiki and a quick google search turns up no help around this
area.  It is unlikely that an average user would ever do a M-x
mailcap-parse-mimetypes for routine work.

Jambunathan K.