Before this commit, you'd have to manually insert the kernel module for
OVS or OF kernel modules, and you couldn't run one regression test with
all 3.
Now, these are kmod insert/remove is handled automatically.
Network may now be used with custom controllers.
An example of doing this is in nox.py, which instantiates at TreeNet
using a custom Controller, NoxController, that runs nox_core rather
than the reference controller.
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).
Renamed examples to make them easier to type!
Bob Lantz
Brandon Heller