Add library medley for handy helpers
Lots of changes

- remove variable arity from all functions except for shiny outer-level.
  It isn't necessary, makes passing data around more difficult, and
  feels wrong.
- support wildcard loads in a namespace. (ex- instead of specifying to
  load a.b.c/a and a.b.c/b, use a.b.c instead.)
- Support passing options through load-streams macro. So far the options
  supported:
    - :env - use explicity passed along environment instead of detecting
      local environment to pass along to child streams.
    - :env-exclude - a list of variable names (as keywords) in the local
      environment that should not be passed on to child streams.
    - :env-only - a list of variable names found in the local
      environment. only variables who's names are found in this list
      should be passed onto children.
    - :env-include - a map of variable names and values that should be
      included with the vars in the local environment. should a conflict
      occur, values in the :env-include map win.
- able to pass arguments to stream constructors in load-streams. (ex-
  (load-streams (bf.rules/my-rule :a :b)))