Tweaked Changes file formatting as per CPAN::Changes::Spec

Hi,

I tweaked the format to conform to CPAN::Changes - the main thing was putting the date of the first release in ISO 8601 date format.

I also changed the header line to match what I've seen in 90%+ of distributions :-)

Cheers,
Neil

PS I'm doing this because I'm on a quest to help improve CPAN:

> http://questhub.io/realm/perl/quest/51f0337718ba7d3959000086