Cleanup dvbpsi_*_Gather*Sections() function to not call dvbpsi_DeleteSections() twice.
The function dvbpsi_decoder_reset() already does that, so there is no need to do it
inside the gather functions when dvbpsi_ReInit*() is called.

Some streams generate invalid program entries in the first PAT.
Ignore these programs and the PAT they are in and reset the PAT decoder.
This way the next PAT (even when the version number has not been incremented)
will be handled by libdvbpsi library.

Various bugs were fixed that made ATSC tables not work optimally if at all.

The documentation states that both 0x42 (this transponder) and 0x46
(other transponder) tables are accepted, but the check is hard-coded
against 0x42. Make it accept both, in the style of the other decoders.
Signed-off-by: Jean-Paul Saman <jpsaman@videolan.org>

MSG_CMSG_CLOEXEC is a flag for recvmsg and not recv. Thus rewrite
{udp,tcp}_open to create sockets with SOCK_CLOEXEC. If SOCK_CLOEXEC is not
available, FD_CLOEXEC is set instead.

The function dvbpsi_CheckPSISection() correctly checked the TOT table, but
not the TDT table. This patch corrects this ommission.

examples/dvbinfo/udp.c: Some OS-es do not support SOL_IP and SOL_IPV6, so provide alternatives for them.

Use explicite parenthesis around ? : constructions.