Touch up some of the docs.

* Make it clear Mite::Compiled and Mite::Source are private.
* Complete the MakeMaker and Module::Build instructions for distribution.
Move the main docs into Mite.pm.

Also touch them up a bit.
Document the Moose features we implement and our Moose extensions.
Make it clear Mite should not be a dependency.
More doc touch ups.

* Document the Class::XSAccessor optimization
* Remove the yet to be fixed problem of Moose roles violating encapsulation.
* Point out Mouse's role in the Moose ecosystem better.

I'd like to add Moo to the SEE ALSO but it doesn't cover any of the
unique features of Mite (no dependencies, fast runtime, fast compile)
better than Mouse.
Clarify what "zero depenencies" means.
Merge branch 'issue/31'