Revert "Revert e7acbde..1361b55"

This reverts commit d3ac8951cfa2f3dd8eb8592672fe55e7655bff3a.
Revert e7acbde..dfee621

This rolls back to commit e7acbde9bfff2741431e20672406ce2b7814ba60.
add socket.io.js