tcpdump 4.6.2

Version bump, optional use of a newer libpcap, culled unrecognised
configure options and mandatory OpenSSL dependency to escape this:

# /usr/local/sbin/tcpdump --version

tcpdump version 4.6.1
libpcap version 1.5.3 - Apple version 47
OpenSSL 0.9.8za 5 Jun 2014

Closes #389.

Signed-off-by: Jack Nagel <jacknagel@gmail.com>