First set of manpage markup fixes

Enclosed patch fixes inappropriate uses of the .SS macro.  Fuller explanation
in the change comment.

There are other problems in these pages that block lifting to
XML-DocBook, most notably in the command synopses.  They will take
some creativity to fix.  I'm working on it

>From 75745adba4b45b87577b61a2daa886dd444f44da Mon Sep 17 00:00:00 2001
From: "Eric S. Raymond" <esr@thyrsus.com>
Date: Fri, 21 Jun 2013 15:27:38 -0400
Subject: [PATCH] Abolish presentation-level misuse of the .SS macro.

This change fixes most (but not all) fatal errors in attempts to lift
the iproute2 manual pages to XML-DocBook.  Where .SS is still used it
is a real subsection header, not just a way to outdent and bold text.
Presentation-level instances are turned into .TP calls and tables.
ss: add more TCP_INFO components

Allow ss -i to display more TCP informations :

unacked:N   Number of un-acked packets
retrans:X/Y   X: number of outstanding retransmit packets
              Y: total number of retransmits for the session
lost:N       Number of lost packets (tcpi_lost)
sacked:N     Number of sacked packets (tcpi_sacked)
facked:N     Number of facked packets (tcpi_facked)
reordering:N Reordering level (if different of 3)

Example :

$ ss -emoi dst 10.7.7.83
tcp   ESTAB      0      1154056   10.7.7.84:54127    10.7.7.83:34342
timer:(on,200ms,0) ino:57003 sk:ffff88063c51d0c0 <->
	 skmem:(r0,rb89280,t0,tb2097152,f726504,w1436184,o0,bl0) ts sack cubic
wscale:7,6 rto:310 rtt:107.375/1 mss:1448 cwnd:568 ssthresh:108 send
61.3Mbps unacked:568 retrans:0/21 reordering:127 rcv_space:29200

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
ip: fix build failure if time_t is not long int

This includes x32, and, per Linus' decree, any future arch with longs
shorter than 64 bits.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>