Big refactor (openai#124)

* massive revision inspired by soup: algo folder works

* porting rl commands, WIP

* various

* git subrepo push [email protected]:openai/codegen.git --branch=refactor codegen

subrepo:
  subdir:   "codegen"
  merged:   "aa27e069"
upstream:
  origin:   "[email protected]:openai/codegen.git"
  branch:   "refactor"
  commit:   "aa27e069"
git-subrepo:
  version:  "0.4.0"
  origin:   "[email protected]:ingydotnet/git-subrepo.git"
  commit:   "74339e8"

* various

* rewrite RL stuff in new framework

* fix almost everything

* woohoo tests pass

* more tests

* reformatting

* fixes

* write tests for embeddings

* re-remove cg2

* pylint

* minor

* move smooth_helpers import; seems to cause nondeterministic failure in parallel pytest