use raco better
updating from master
simple exception test for ws
Small changes supporting docs and module system cleanups

- Use collection path pyret/lang/pyret-lib/libs for built-in libraries
- Include that in test-utils and languages
- Create some more dead code in desugar.rkt (now libs are always included)
- Provide some extra stuff from eval to be used in docs
this stuff is way out of date; we should just go into history to find it in the future if needed
dabbling in scribble stuff for pyret
now that we do some ws builds, ignore web stuff