urldecode static filenames

if a filename is urlencoded because of spaces and other pesky characters, we need to decode it before trying to find the accompanying file on disk
Merge pull request #125 from caleb/master

urldecode static filenames
allow to upgrade a connection to a web socket with a cowboy web socket handler
add web socket client library to test websockets
test upgrading a connection to a web socket
create router macro to simplify routing to a websocket handler
test websocket router macro
add bare bone test for web sockets
WIP: write web socket tests using cowboy web socket callbacks API
fixed send message test