fix equality operator
Add start of basic drawing API:

* move to sending EDN from server to browser
* move unload handler to separate ns
* pull in cake.js
* add experimental circle method (see code below)
* break message log (will fix in next commit)
* have fun!

(1..20).each do |idx|
  circle idx*4, idx*4, idx*10
end
Tidy things up:

* don't draw green circle
* remove photo button
* fix bug in ws handler