Adds license missing license header and updates NOTICE/LICENSE files.
Removes reference to Socket.IO from LICENSE as we replaced SOCKET.IO with Atmosphere.
Adds reference for Atmosphere in LICENSE.bin.
Sets project version to 0.4.0.
Updates CHANGES for RC6.
Updates my GPG key.
Formats the version number according to Sematic versioning.
Changes version on master to 0.4.0.