Move get_registry_port from client to driver
Move is_daemon_running from client to driver
Simplify socket connection class code
Drop configurable stop_container timeout

Nobody was using it, anyways.
Add note about infinite loop
Add tests for DockerHTTPClient
Reinitialize UnixHTTPConnection per request
Merge pull request #11 from bcwaldon/client-testing

Testing of DockerHTTPClient & other small refactoring