This commit also changes the PcapDumper to automatically flush after
every called to Dump(). This is because pcap_dump has an internal buffer
of some sort that only writes to the file after a set amount of bytes.
When using the new option on a low-traffic network, it might be a while
before you see any packets written since it has to overcome that buffer
limit first.
General changes:
* Add -D/--deterministic command line option as
convenience/alternative to -G/--load-seeds (i.e. no file needed, it just
uses zero-initialized random seeds). It also changes Broker data
stores over to using deterministic timing rather than real time.
* Add option to make Reporter abort on runtime scripting errors
