When IPv6 support was introduced in commit 7e88477439 apparantly the
output to addresses that were not multicast was broken. This commit
fixes the regression.

This patch adds support for connecting to CAMD over IPv6. Nice addition
is that now tsdecrypt tries each of the addresses returned when CAMD
hostname is resolved and connects to the one that works. Resolving
of the server address is done before each connect, which allows for
uninterupted migration of CAMD servers by just changing their DNS
record.

IPv6 functionality can be disabled by using -4/--ipv4 options or
if you fancy only IPv6 servers -6/--ipv6 can be used.

The limitation is that resolving the hostname is performed only
once at tsdecrypt startup. If DNS changes while tsdecrypt is running,
tsdecrypt won't notice that.

The option correct option is --no-output-filter.

By using this option output can be disabled if there is no currently
received code word.

Use "make ffdecsa" to build tsdecrypt with ffdecsa support
or "make dvbcsa" to build with libdvbcsa (this is still the default).

When the input is MPTS and output filtering is enabled, rewrite output
PAT to include only the single program that is decoded.

This workaround is no longer needed because camd socket is now set
TCP_NODELAY and this fixes OSCAM communication.