Standarize on 'content' for all templates

I attempted this standardization in 4d9bd8d2. Looks like I missed
these 2.
Read UTF grid plot ID key from config

The name of the plot id field in the UTF grid changed, so rather than
just update it, I moved the field name out to settings.js.
Force tree layer to refresh on filter change

Without {force: true} the layer was not updating until the map was
panned or zoomed.
Merge pull request #112 from jwalgran/fix/force-layer-refresh

Force tree layer to refresh on filter change
Merge pull request #111 from jwalgran/fix/utf-plot-id

Read UTF grid plot ID key from config
Set up login/logout and profile redirect

Django auth, by default, redirects a successful login to
/accounts/profile/. I set up a redirect from /accounts/profile/ to
/users/{logged-in-users-username} so that we have a consistant URL
for viewing both the page for the logged in user and any other user
page.

If a user is not logged in /accounts/profile/ redirects to
settings.LOGIN_URL
Merge pull request #108 from jwalgran/topic/login-workflow

Login workflow