* Theory: Describe LMT, cutoffs, zone.tab, and time.tab better.

Following discussion by Lester Caine in
<http://mm.icann.org/pipermail/tz/2013-August/019716.html>
and Garrett Wollman in
<http://mm.icann.org/pipermail/tz/2013-August/019715.html>.
* Theory: Improve citation to Morrison & Stephenson.

Mention the 1972 UTC transition.  See Steve Allen in
<http://mm.icann.org/pipermail/tz/2013-September/019770.html>.
* backward: Move some links back to primary files.

This should allay concerns that the links would go away any time soon.
Suggested by Stephen Colebourne in
<http://mm.icann.org/pipermail/tz/2013-September/019801.html>.
Change "`" to "'"; these days, "`" and "'" are not symmetric.
* antarctica (Antarctica/McMurdo):
* europe (Europe/Jersey, Europe/Guernsey, Europe/Isle_of_Man)
(Europe/Mariehamn, Europe/Busingen, Europe/Vatican, Europe/San_Marino)
(Arctic/Longyearbyen, Europe/Ljubljana, Europe/Podgorica)
(Europe/Sarajevo, Europe/Skopje, Europe/Zagreb, Europe/Bratislava):
* northamerica (America/St_Barthelemy, America/Marigot):
* southamerica (America/Lower_Princes, America/Kralendijk):
Move here from 'backward'.  This reverts a 2013-08-09 change.
Replace some zones with links when that doesn't lose non-LMT info.

* northamerica (America/Anguilla, America/Dominica, America/Grenada)
(America/Guadeloupe, America/Montserrat, America/St_Kitts)
(America/St_Lucia, America/St_Vincent, America/Tortola)
(America/St_Thomas):
Link to America/Port_of_Spain instead of having a separate zone
that differs only in LMT.  Each LMT entry is just a placeholder for
unavailable info, and by itself does not justify a separate zone.
Using just one zone simplifies maintenance, makes the runtime
a bit smaller, and can help simplify user selection of zones.
* southamerica (America/Aruba): Likewise, for America/Curacao.
* backward (America/Virgin):
* northamerica (America/St_Barthelemy, America/Marigot):
Adjust to the other changes, by not linking to a link.
* australasia (Pacific/Johnston): Now a link to Pacific/Honolulu.

The old, standalone entry was demonstrably wrong, and the link
is more nearly right.  Problem reported by Andrew Main (Zefram) in
<http://mm.icann.org/pipermail/tz/2013-September/019817.html>.
Document some longstanding unwritten guidelines.

These come from POSIX or similar platforms, or from the standard
'zic' implementation, but never got written down anywhere.
* Theory: Document other POSIX-inspired restrictions on names.
* zic.8 (DESCRIPTION): Document that zic's behavior is unspecified
if some names are duplicates.  Sometimes it complains, sometimes not.