Accepting all positive HTTP status

201 is as good as 200 :-)
Propagating the HTTP status code for success as well.
Using sinon.xhr to fake XHR response status code.

ISO tests for the moment.
Adding tests for 202 response and 300 response.
Merged in changes from pull request #161. Implementation was merged OK, but I had to manually make changes to the tests
Merge pull request #179 from fmtvp/oncletom-patch-1

Accepting all positive HTTP status.

Internal ref: TVPJSFRMWK-1999