Various dist improvements

Hi,

I've made a number of changes to your dist:

 * Abstract now follows the accepted pod conventions
 * Added github repo to metadata and doc
 * Min perl version 5.6.0
 * License type now specified in metadata

I was prompted to do this by the abstract issue - not following the convention means your module isn't presented in the usual way by MetaCPAN or search.cpan.org.

Cheers,
Neil