fix bug 1066512 - Use setInterval for dirtiness checks, check all fieds

https://bugzilla.mozilla.org/show_bug.cgi?id=1066512

At the moment, I see two issues with our dirtiness checker:

1.  If the user opens an edit page and updates a link via dialog (i.e. doesn't type anything into the editor), the dirtiness checker doesn't go off.  Our version of CKE doesn't provide a "change" event for the editor so `setInterval` is probably our best bet.  I'm somewhat worried about performance of setInterval but I'm clearing the interval upon unload and we'll see what our admin users say.

2.  If you go into a doc and only check one of the review checkboxes, for example, or add a revision comment, the dirtiness checker doesn't run because it was only checking metadata fields.  I'm now checking all fields.