better info/error messages, client :verbose option
allow binding server to different address

default to 127.0.0.1 for 'safety', because we don't want spammers sending
{:op :print :value "BUY VIAGRA CHEAP $1 $1 http://goatse.cx"} to every
cljs developer's port 9001 or something

should probably make a note of this in the README, for the case of
REPLing with a mobile device
reset connection state in cljs when WS closes
refactor :ready to use with-compiler-env
implement load-javascript, :preloaded-libs option
re-order and privatize some vars