The link tag being produced was not W3 compliant as it was using the nofollow value in the rel attribute on a link tag which is not permitted as per the W3 standards http://www.w3.org/TR/html5/links.html#linkTypes
Deprecate the getDiffedChanges method to get rid of confusing
fullHistory parameter. Add a getDiff method to fetch just a single diff
and a more versatile getDiffList method which allows specifying a limit.
We now also cap the amount of items coming from the diffing process
to a default value that we hope will result in generation times no
greater than a few seconds. This can be reconfigured by developers.
