Much Needed Tests

Here are two tests for:
1. The logic of the messenger functions.
2. Checking that messaging works as a whole.

With the constant changes to core lately, and how new these tests are, it's hard to be sure
if the tests are faulty, or if it's core itself. But the tests seem to be functioning properly for now,
and should report errors correctly.

These *should* compile under cygwin, but they were meant to be run by travis after each request,
not by each developer before a pull request.

Since these tests **will** fail the current master branch for accepting the binary string of an ID way too short,
the changes to .travis.yml will have to come in a different PR, or this build will never pass.