bump version to 0.8.2-dev, refactor debugging, make dryrun cover a bit more code.
Remove unittest fakes for now, make MainTest use a real loader.

Also update the 'pragma: untested' blocks to reflect the stuff
that is now truly untested due to the interaction between coverage
and the debugger; coverage is up to 95% otherwise.
add -v, --no3 flags to run
make tools/cov --show imply --show-missing
add more tests for Host, FakeHost
add test for spawn_main
add tests for pool