when initializing first site, set name to localhost

 Because site model validates presence of name, we need to set it upon
 creation.

 To setup the db for multisite, use rake db:migrate to revert to before
 multisite was available and then db:migrate to re-apply migrations:

 rake db:migrate VERSION=20120831234448
 rake db:migrate

 Now 'rails db' followed by 'select * from sites;' should show a line
 starting with:

 1|localhost|localhost
Removed extraneous '.html' in call to render.

This change should get rid of the following backend warning while
hitting the site:

DEPRECATION WARNING: Passing the format in the template name is deprecated.
Please pass render with :formats => [:html] instead. (called from
_themes_activate_views_layouts_application_html_haml__4194966187427972843_70245131629280
at themes/activate/views/layouts/application.html.haml:113)