Reset location generation seed everytime top-level interp is called so that bools and none work properly when running multiple programs in succession (basically when running the tests).
move syntactic sugar into utils, and make-builtin-num
Experimental style for writing libraries

- Several macros for surface-python to be used in pylibs:

  ___delta(str, arg, ...)

  =>

  (CBuiltinPrim str (list arg ...))

  Rationale: it would be nice to write Python libraries that have access to
  our internal primitives.  See pylibs/tuple.py.

  ___id(str)

  =>

  (CId str (GlobalId))

  Rationale: it would be nice to write Python libraries that can reference
  "special" identifiers, like the to-be-implemented %class, etc.

- An implementation of tuple.rkt in Python (pylib/tuple.py)

- Memoized the loading of Python libraries so that after the first run through
  parsing and desugaring them, future calls to interp re-use that 4 seconds of
  work

- removed "return self" from SeqIter.__init__

- upgraded the timeout to 10s, since the first load can take some time
Merge branch 'scope-rewrite' of github.com:brownplt/lambda-py into scope-rewrite
fixing small type errors from b3e0af388dcb616bf666974430cd79dcddcc426e