Misc distribution udpates

Some small changes:

* `Changes` file now satisfies `CPAN::Changes::Spec` (see commit message). There is a special [online service to check your CPAN uploads](http://changes.cpanhq.org/author/ROCKY) for correctness of the changelog.
* Ditch old `$obj = new Some::Class` syntax from Pod & tests

This PR is part of my [advent quest](https://questhub.io/realm/perl/quest/547b4202070ccf750d00010e).

Cheers,
Sergey