detect_lowlevel.py files

[Jaison Lee]

Has there been discussion concerning duplication of effort in the
various detect_lowlevel.py files for the various operating systems?
They will always be different of course, but right now these files
bare no resemblence to each other whatsoever. :)

Also, has there been discussion on what to do with common tests across
operating systems? These could either be combined into the upper level
lowlevel.py, or have different (identical) checks for each OS. Either
way is perfectly workable, but I don't think we should try to mix
both, or else it would be difficult to determine the location of
tests.

I would lean in favor of keeping all tests separate myself. The
downside is duplication of identical tests, but the reality is that
few developers will have the ability to test for every targetted OS.
It also preemptively solves the problem of dealing with tests that
work for several but not all targetted OS.