render_to_response does not work on newer django, so it needs to be
replaced. And using a speicfic context actually overcomplicates things,
it's easier to just use a wrapper function. For those cases where we
don't need NavContext, just use render() (the new shortcut function from
django), which also removes the need to use RequestContext.
This one will validate that the url is under /accounts/, which is
the only part we are going to be excluding from caching once we
move the website to https-only.
This was broken before, but older django versions didn't notice it was
wrong and just ignored it. 1.8 throws an error, so now is a good time to
fix it.
