distributed chat project
routing for static files
websocket and data exchange between client and server
build UI
join to chat, switch stages
join with name and leave
send/receive msg
process user join/leave
use switch instead of if
small improvements on chat client
use lager
dchat gen_server, keep online users and history, broadcast events
send online list and history to client on join
Merge branch 'master' of github.com:yzh44yzh/erlang-school