Use setuptools to install python files
Now, to reference mininet files, use 'import mininet.mininet'.
PYTHONPATH mods are no longer required for installation.
First crack at allowing Controller to be customized.Network may now be used with custom controllers.An example of doing this is in nox.py, which instantiates at TreeNetusing a custom Controller, NoxController, that runs nox_core ratherthan the reference controller.
Cleanup of doc files.Fixed xterm.py (and cleanup) to clean up screen sessions.Cleaned up sshd.py (though interface is still in flux.)Added 1024-node network example (treenet1024.py).Added example showing multiple tests on a single network (multitest.py)....