Fix the POD formatting and big doc mistakes.

* Method body documentation was indented as code.
* type_does docs were redundant with type_isa
* +<> isn't valid POD formatting
* Improved some of the English
Editorial work on the POD.

Switched to a style of listing just the method name in the header.  This makes it
easier to search for and link to.  It also allows for a more expansive explaination
of the interface illustrating what is required and what is optional.

Document that there is a default test name.
Merge pull request #3 from schwern/cleanup_docs

Cleanup docs