update deps, reorg project files/config, and more

- remove lein-ring. focus on uberjar builds only (no war support now)
  while also allowing easy swapping out of standard jetty for
  jetty-async (thus, removal of lein-ring which does not support this)
- "downgrade" to clojure/tools.logging. mainly out of preference for
  having logging work with dependencies using older logging solutions
  "out of the box" and using plain old log4j configuration
update README.md
version 0.4