complete tests

[cinayakoshka]

Most of the tests are outdated beyond belief. Rewriting them following a grand simplification of the test suite (which eliminated the unnecessary complexity of FakeServer) is still incomplete. Finish this so we can have a stable repo with no more incomplete repairs in it (except for the Sample class, which isn't done at all).

With the simplification, we now need to test the following

• request semantics
• response handling
  with everything between.

This could be more detailed, but it's good enough for now.