Fix the recaptcha registration URL.

Apparently google moved the registration page for recaptcha and didn't keep the
old URL functional. Trivial fix.

Fixes bug 3471.
Don't assume that profiles exist in datagrid code.

If a new user was created but the associated profile was not, loading the
dashboard would cause an error (because in 1.7.x, `User.get_profile()` won't
create the profile). This is already fixed in the 2.0.x series, because we've
completely replaced `User.get_profile()` there.

There are numerious other places where the profile is assumed to exist, but
this is the only one that we've encountered in production.

Testing done:
Ran unit tests.

Fixes bug 3083.

Reviewed at https://reviews.reviewboard.org/r/6111/
Expose all users in the UserResource for public LocalSites.

The addition of public local sites exposed a bunch of assumptions in the user
linking. By default, the user resource within a local site only contains those
users who are actually members of the site. This causes a bunch of bizarre bugs
in rbtools or other consumers of the API, because the links between objects
(such as the review request submitter) could be 404.

This change makes it so that if a local site is public, all users on the server
are exposed in the site's user resource.

Testing done:
Verified that links no longer 404 using cURL. I intend to add a unit test for
this when porting to 2.0.x (since the API testing framework there is much
improved over 1.7.x's)

Fixes bug 3484

Reviewed at https://reviews.reviewboard.org/r/6110/
Update for the new support page infrastructure.

This updates Review Board to work with the new support infrastructure
being deployed on our servers.

rb-site now asks for a Company name, which can also be provided later on
the General Settings page. This name will show up on the support page
when users visit it. We may also want to use this down the road to help
brand Review Board itself.

rb-site will also ask for permission to collect support data, and
explain what we collect and how it's used. This can be changed later
through a checkbox on the Support Settings page. If allowed, rb-site
will up and maintain the support page on install and upgrade.

Reviewed at https://reviews.reviewboard.org/r/6015/
Point users to Power Pack and support contracts after a site install.

After a user installs a site with 'rb-site install', they're now given
links to Power Pack and to our support contracts page. These are
benefits that we historically haven't done a great job pointing new
users to, so we want them to at least know about them as they're getting
going.

We even make the Power Pack trial process a bit easier by giving users
their install key up-front.

Reviewed at https://reviews.reviewboard.org/r/6020/
Include the Python version in the support tracking data.

The Python version is now sent along with the other support data, in
order to better track issues and see what versions of Python are still
being in use.

Reviewed at https://reviews.reviewboard.org/r/6038/