The hope is that this will make the results a bit more consistent
when running in a VM environment.

Background: the reference controller is reactive and installs exact
match rules. By attempting to start a telnet session we make sure that
the ARP caches and TCP flow rules are set up (in one direction at
least) before the test starts.

This is intended to help with #413

add 1ms delay to all links to exaggerate TCP bandwidth decrease across an increasing number of links

I wasn't sure this was worth fixing at first, but it does look more readable
now.

Note: we should probably rename it "setup()" to avoid confusion.

Now, to reference mininet files, use 'import mininet.mininet'.

PYTHONPATH mods are no longer required for installation.

Added commentary on control network to mininet.py.
Hopefully fixed linearbandwidth.py for real.

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!

Minor tweaks to other files.

More tweaks for examples, which are still in progress.

Added new example to create xterms.
Other minor changes.