ECDR-20:  Added in a parameter to the search and broker endpoint that al...

...lows the client to specify if they want the georss results to be returned as GML or as Simple GeoRSS.

Note - The only change to the AbstractAtomTransformer was adding a new method that checks the parameter value and uses that or falls back to the default if no parameter was passed in.  I accidentally formatted the file with my formatter that adds in spaces, so it looks like there is a lot of changes in there.

Didn't add any unit tests at this time, but will create a ticket for that.

<!-- Reviewable:start -->
[<img src="https://reviewable.io/review_button.png" height=40 alt="Review on Reviewable"/>](https://reviewable.io/reviews/di2e/ecdr/4)
<!-- Reviewable:end -->