closes #81

In case matching field is not found, clear (set to null) references to faulty DMH.
Long term, should replace such DMH's with instances that will throw more meaningful
error messages at runtime.

Adding support for extra classes being redefined to the test framework.
Rewriting lambda test a little, extracting classes with lambda's to top
level.

Same fix as for static fields, update offset directly
in the DirectMethodHandle$Accessor.

 * Killing test suites (you can run tests by package)
 * Introduced categories to run certain tests only on 'light'/'full'

Well, dcevm.org domain is lost, so let's use com.github.dcevm for now.