Pipelet._transactional_fetch():
  - Do not emit to receiver_pipelet unless there are values or a transaction_id in options
    This prevents sending empty add sequences
  - Improve documentation

uglify(): add ToDos for the use of transactions between emited files and emiteds uglified files
test/http.js: display cookie from socket.io handshake
Merge branch 'master' of https://github.com/ConnectedSets/ConnectedSets