Rename three lettuce files
Upgrade lettuce to 0.2.15 in pip requirments
Comment out a pair of unused urls in urls/rsr.py

I'm commenting out a pair of widget URLs I don't think are implemented.
Remove superfluous world.browser call

And some small feature text tweaking
[#169] Add programmatically generated site covering smoke test

Add a set of functions to generate a feature file that contains steps
to visit most of RSR and a partner site

See comments in the features/smoke_tests/__init__.py and
features/terrain.py for details of how it works