pdump: support pcapng and filtering

pdump: support pcapng and filtering

This enhances the DPDK pdump library to support new
pcapng format and filtering via BPF.

The internal client/server protocol is changed to support
two versions: the original pdump basic version and a
new pcapng version.

The internal version number (not part of exposed API or ABI)
is intentionally increased to cause any attempt to try
mismatched primary/secondary process to fail.

Add new API to do allow filtering of captured packets with
DPDK BPF (eBPF) filter program. It keeps statistics
on packets captured, filtered, and missed (because ring was full).

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: Reshma Pattan <reshma.pattan@intel.com>
Acked-by: Ray Kinsella <mdr@ashroe.eu>