add class lineage checking to attributes

Ensure that any class names given to our attributes (e.g. via the constructor
or back from a builder) are actual descendents of the original related class.
whitespace, POD updates
add a missing coerce; bump minimum MXAS req to 0.019

...as we need that for inline constraints + coercions to work.
drop parallel test runs -- travis build issue
remove an errant test class that snuck into our requires
v0.004

	* add constraint checking to ensure that our classes, as stored, are
	  actually related to the original related class
Full build of CPAN release 0.004