Reformatted Changes file as per CPAN::Changes::Spec

Hi,

I've made the following changes so the Changes file conforms to CPAN::Changes::Spec

 * Changed format of existing entries
 * Changed NextRelease format so future updates conform

I think this is a lot more easily read by humans, and by following this format, various tools like CPAN will be able to process it as well.

Cheers,
Neil