This removes the global logger (which by the way was deleted when the first tox
was killed, so other toxes would then stop logging). Various bits of the code
now carry a logger or pass it around. It's a bit less transparent now, but now
there is no need to have a global logger, and clients can decide what to log and
where.
Also, fix the hstox build that was taking half an hour. It now takes 5 minutes.
Also, perform distcheck on travis to ensure that make dist works. It's not
actually failing the build at the moment due to broken tests.
