rubydns no longer works in pipelining tests

[alexdalitz]

A while ago, @nwitkowski added some test code for TCP pipelinining, based on @ioquatix rubydns library. Sadly, the interfaces changed, and the code (plus subsequent changes) no longer works in the tests.
I've spent some time looking at this, and can't get the breaking changes fixed. As a result, I've removed the tests that use rubydnsm, in this commit : 06a23f9

If anybody is able to contribute patches which fix the broken API changes, so I can reinstate this test, I'd be very grateful.

Thanks!

[ioquatix]

What is not working?