Post david fixes

This addresses some issues that came up during my site review with David yesterday:
* A few really annoying tests were fixed.
* Post a job is now in the topbar. Also, displaying postajob in the topbar is based on prm_access and product_access permissions. This requires the request object, which I have confirmed is being passed to the template in every case. We may want to move the "Purchased Microsite" out from under the "Employer" heading, but for now that's where it stays.
* Post a job has been removed from the purchased microsite admin navigation (since they don't really need it).
* Fixed the cancel button for offline purchases.
* Removed the url for a job if the job hasn't been approved yet.
* Removed clickable rows and instead made them all have action links to view/edit.
* Number of jobs for product can no longer be negative and product prices must be over $1.
* The "Add Jobs" link has been removed when no more jobs can be added to a product.


All tests pass