Enhance product view

* fix the layout so it has the analyzer navbar on the left
* switch the form to use .as_p() which makes it a tiny bit easier to use
* tweak the view code so that it makes it easier to update existing
  products
* add some "helpful" directions so it's a little clearer as to what's
  going on

This improves on what Ian did just to make it a little easier to use.

r?
This checks to see if there is an object which happens if this HTTP request had a pk querystring parameter. If it does, then adds "instance" to the form kwargs which causes the form to have that product's values in the fields.