Muzzle should fail on unimplemented abstract methods

[mateuszrzeszutek]

This is an idea for improvement that would have prevented something like #1083 from happening.
In that issue, Servlet API 3.1 introduced two new abstract methods to ServletOutputStream that were unimplemented in our code -- and everything was OK until someone tried to call one of them.

I believe that muzzle should fail for an instrumentation if one of our classes that implements/extends some lib/framework class has missing methods.