Remove %_Test global, set to $self->{Tests}

This allows for Moose::Role, or other such behavior, to override
either a) the instances of this class, or b) class behavior via
Moose::Meta::Class->create.

This should also help eliminate the 'internals broken problem'
that can occur during some inheritance paths.
Subroutines should be methods when they can

Allow sub classes and roles to override the way that Test::Class
works should someone need to do so.

Modifying behavior (additional logging, etc), should be easy and
not require the modification of Test::Class to be able to do it.
Tests using Moose::Role.

Demonstrate a few benefits of the changes.
Remove Moose dependency in test.
Separate running tests per class into own method

This modification allows someone trying to add
debugging on a per class basis, or to override
behavior in various ways that I might not be
able to anticipate.
Merge pull request #1 from paulsalcido/allow-role-modifications

Allow Moose::Role style modifications to class instances