Have a Users page that lists all the users on a given install

[Karen Rustad]

Right now, I have no way of telling how many users are on the site
or any way of seeing their profiles (other than clicking on another
user's photo and clicking their name on the photo page). If we're
going to have user profiles, let's have a way of finding other
users!

[Will Kahn-Greene]

The original url for this bug was ​http://bugs.foocorp.net/issues/470 .

[Sacha]

I made these changes, but I changed pagination.html so the paging widget now says "Next" and "Previous" instead of "Older" and "Newer"

Older and Newer just don't make sense for a list of users.

Also, this probably needs looking at by graphics/templating folks for two reasons:

1. this page is only accessible by going to the /userlist.html page directly, there are no links to this list.

2. It's a little ugly right now. Maybe a profile picture or something the user uploaded?

Changes are here:
​https://gitorious.org/~chemhacker/mediagoblin/chemhackers-mediagoblin/commits/bug178_userlist