renamed chat_sample to chat_app

Ignore-this: e8ddfd2d706a9d48bd6c9ec2539c818b

also changed script_sample to app_editor

darcs-hash:20140123032326-c21fe-e54cdcd0ec8441b1910935f3dc795c1dbfac3399
added timestamp to chat messages

Ignore-this: a5efff1b71d544cb6bee2ffb8f9e0b02

darcs-hash:20140123032446-c21fe-3068678d5315454db5b4165206ea38927382412c