The former regex for the gateway did not include the '-' character,
so it did not work on English Vista/Win7 systems where the gateway
is shown as "On-link". We now allow any text in the gateway column.

Either False, or True or a function to be applied to Raw.load

Putting do_graph() in arch.windows.__init__.py and
monkey-patching the original version did not work,
so we use "if WINDOWS:" clauses instead.

pylibpcap and pcapy offer a 'to_ms' parameter to set the read
timeout in milliseconds, but standard pypcap does not.
(Instead there is the 'immediate' parameter to disable buffering.)
A specially patched pcap version was made for Scapy which adds a
timeout_ms parameter, but to stay compatible with pypcap it has a
different position in the argument list than in pylibpcap
and pcapy.
So we have to distinguish four different Python bindings for
libpcap/WinPcap.