More flexible logging support
Use customized StreamHandler from Python logging module to printonly messages for the specified loglevel to the console.
Clean up display
Don't print retry errors by default.
Don't attempt to kill processes twice
Was causing OSErrors because the process to kill no longer existed.
Reduce interface move delay and make configurable
Much faster now; from 1 s delay to 100 us.
Add example unit tests and Makefile target
Use setuptools to install python files
Now, to reference mininet files, use 'import mininet.mininet'.
PYTHONPATH mods are no longer required for installation.