Added Changes file and ensure repo link in metadata

Hi,

I've added a skeleton Changes file that conforms to CPAN::Changes::Spec.

I also added the repository details to Makefile.PL, which should result in it being included in the dist's metadata (I don't have RT installed, so couldn't run perl Makefile.PL to confirm this. I followed [Gabor's instructions](http://perlmaven.com/how-to-add-link-to-version-control-system-of-a-cpan-distributions) for adding the repo details.

Cheers,
Neil