Changed desugar to ensure stararg is a tuple, Fixes #19
Added regression test functions/non_tuple_starag.py
NB: the tuple constructor is used for the conversion, which should be generalized to work with any iterable.
Added duplicate keyword arguments check on calls
Fixed Exception handling at stararg evaluation
Merge branch 'lex-ragg' of git://github.com/jmillikan/lambda-py
add install section to README
Change heap representation to be more amenable to serialization

- Store is now a pair of ((hashof address value), address)
- The address stored always represents the next address to allocate at
- Two helpers, alloc and update, provide the abstract interface to putting new
  locations on and updating existing locations
- method.rkt isn't used anywhere, and I removed it to avoid refactoring its
  allocations.
String handling into separate lexer, fixing some dequoting
Merge branch 'master' of https://github.com/brownplt/lambda-py into lex-ragg