Chall changes
Fetch working for Models and Collections
Improved error messages for unhandled errors

I got really sick of having to dig through my postgres logs for the real
errors.  We can undo this later if we'd prefer to not expose these errors.
Got PATCH working

Required adding a couple of depenencies.  Specifically browserify and
jiff.  Jiff is a handy library for creating and applying JSON
patches (as per the RFC).  Browserify allows most npm modules to be
packaged and used in the browser - among other things.

Currently, our patch does not support xTuple's locking mechanisms.  I
haven't quite figured out how to aquire the etags required for them to
work.