This patch moves the code for opening an input protobuf packet trace into
a function defined in the protobuf library. This is because the code is
commonly used in decode scripts and is independent of the src protobuf
message.
This patch changes the decode script to output the optional fields of
the proto message Packet, namely id and flags. The flags field is set
by the communication monitor.
The id field is useful for CPU trace experiments, e.g. linking the
fetch side to decode side. It had to be renamed because it clashes
with a built in python function id() for getting the "identity" of an
object.
This patch also takes a few common function definitions out from the
multiple scripts and adds them to a protolib python module.
