Integration test for TorInfo speaking through TorControlProtocol
Strip trailing "OK" lines from most protocol messages.
Closes #8 and long-standing TODO item.
documentation tweaks
add an api_version kwarg to TorControlProtocol to enable future changes
Send signal SIGTERM instead of SIGKILL when timing out.

If the signal SIGKILL is send to Tor and you are using pluggable transports,
the pluggable transports will stay running and not be terminated.
Fix unit-test for hellais' KILL vs. TERM enhancement.