Add explanatory copy to add/edit picture pages saying that tags are comma-separated

[Karen Rustad]

It's not obvious whether tags are comma-separated or
space-separated, just by looking. Let's add a little bit of text to
make that clear!

[Shawn Khan]

issue_467.patch

[Shawn Khan]

Changed the title of the Tags area to be more descriptive and have
people be aware of comma separated for the media.

[Jef van Schendel]

Hi Shawn! Thanks for picking this up, it needs fixing.

I think though that we should keep the "Tags" title the same and
instead add a description.

We'll probably add an actual "description" space because several
other fields also need those. Since the descriptions are going to
be a bit longer than the titles, we can make the text for those a
bit smaller. It could look something like this:

`http://schendje.fedorapeople.org/temp/Screenshot-12.png <http://schendje.fedorapeople.org/temp/Screenshot-12.png>`_

After we integrate proper descriptions, I can easily finish this
bug, so I'll assign it to me, if that's okay?

[Jef van Schendel]

Assigning to me.

[Jef van Schendel]

Fixed in mediagoblin/edit/forms.py and mediagoblin/submit/forms.py
(both the Edit form and the Submit form).

[Will Kahn-Greene]

The original url for this bug was ​http://bugs.foocorp.net/issues/467 .