Defining custom topologies, switch types, controllers, and hosts is now
much easier.  Plus, all Ripcord-specific stuff has been moved out.

'unpep8' script, which does most of the work.

- topo.py is still in pep8
- not all examples work, but this is due to other issues

Updated other files accordingly.

It's possible that mn_clean is a bit easier to read; mnclean may be easier
to type, however.

Added variables to Makefile so that source files are listed in a single
location.

This required a change to logging, which now uses a singleton pattern.

For all future checkins, 'make codecheck' should pass.

Switches and controller in root namespace only, for now.

Possibly useful for adding custom port mappings.

Now you can run a controller on a remote PC that is
not on the same pc as Mininet.

Also use indexing for DPIDs to avoid zeroed MAC

Auto MAC setup sets each host MAC equal to its DPID, which simplifies
debugging.

Auto ARP setup removes the need for broadcast support for ARP, which
enables a smaller NOX controller.

If ripcord.dctopo imports properly, then include its topologies in the
list of available ones.  Also replace topo.py with new generic
topologies and update paths.

Also simplify test running.

Also remove usused imports and outdated doc text.

Simplifies launching a Mininet or running tests on one.