convienience object::at() overload
first test for delta protocol implementation
PubSub.update() for insert, update, delete on arrays
update, delete, insert for objects
update_range and delete_range
finished PubSub.update()
moved pubsub client library
client is ready for updates
some convienience functions for json::array
output for node
configurator::max_update_size
session uses delta encoding, when possible
fixed delta test