Squashed commit of the following:

commit d14a8a37daa4eff712f77c22acc7906de09eac47
Author: Kam Kasravi <kamkasravi@yahoo.com>
Date:   Tue Aug 19 18:15:16 2014 -0700

    Define all GET noArgs to return BAD_REQUEST when a path component is missing
I may be lost in the shuffle here, but I thought the exception mapper was to handle uncaught exceptions. I don't think we should throw an exception just to have it mapped to a fixed code. Just return the fixed code. Usually the response can just be empty. In some cases it can carry a message specifying the error. Is that the role of `ErrorResponse`? then it seems useful.

I had previously wondered if it was necessary to handle things like an empty path or request separately like this. I don't mind doing so -- returning 400 instead of 404. I suppose we'll see if that gets complex. But that's a separate issue I think. Either way there will be cases where we want to return a certain error status and some text and it shouldn't require throwing an exception IMHO.