net: Add ProcessingException for dropping packets

Process.process(Packet<T> packet) has changed signature to allow
throwing of ProcessingException to indicate that packet data was
malformed and couldn't be processed correctly.
net: Add Utils class to consumer

This patch adds a single static method, process(), similar to
Process.Utils.process(), which delegates processing to the provided
Process object but does not maintain a collection of packets to return.

Also, AbstractConsumer now implements the collection version of
process(), delegating to Consumer.Utils.process() (described above),
removing the need for typical implementations to add boilerplate code.
net: Reduce boilerplate required for classes extending AbstractWorker

AbstractWorker now implements the multi-packet process() method,
delegating to Process.Utils.process().
node: Manage Lookup in AbstractNode

This removes some boilerplate from AbstractProducer and allows classes
extending any of Abstract{Producer,Worker,Consumer} to manage content in
a consistent manner.
node: Reduce boilerplate required to implement AbstractNode
efbp: Format files to default Eclipse settings