Adjust dependencies a bit.
- bump clojure up to the latest-greatest 1.5.1
- bump lwjgl to latest-greatest 2.9.0
- drop overtone back down to the latest released version 0.8.1, and
- add leipzig 0.4.0 for example fun
add leipzig drum machine
move cool demo up a bit.
tweak a bit
Add license file.
Update readme for the :previous-frame and some other recent changes.