northamerica: move America/Shiprock to 'backward'

This fixes the 2013-08-15 change so that 'make check' works again.
* backward (America/Shiprock): Move this link here....
* northamerica (America/Shiprock): ... to here.
Move obsolescent Americas entries to 'backward'.

This continues in the series of moving entries to 'backward' if
they exist only because of obsolete tz rules about country codes.
In this case, Zone entries are changed to Links; this doesn't
affect any post-1970 time stamps, and the pre-1970 time stamps
are out of scope and are often of dubious reliability.
* backward, northamerica, southamerica (America/Anguilla)
(America/Antigua, America/Aruba, America/Blanc-Sablon)
(America/Cayman, America/Curacao, America/Dominica)
(America/Grenada, America/Guadeloupe, America/Montserrat)
(America/Port_of_Spain, America/St_Kitts, America/St_Lucia)
(America/St_Thomas, America/St_Vincent, America/Tortola):
Now 'backward' links to America/Puerto_Rico.
(America/Atikokan): Now a 'backward' link to America/Panama.
(America/Creston): Now a 'backward' link to America/Phoenix.
(America/Nassau): Now a 'backward' link to America/Toronto.
* backward (America/Coral_Harbour, America/Kralendijk)
(America/Lower_Princes, America/Marigot, America/St_Barthelemy)
(America/Virgin): Adjust to avoid link-to-a-link.
Move obsolescent Montreal entry to 'backward'.

This is like the previous change, except it entails a change to zone.tab.
The America/Montreal entry was created only because we mistakenly
thought that Montreal's and Toronto's post-1970 time stamps differed.
* backward, northamerica (America/Montreal):
Now a 'backward' link to America/Toronto.
* northamerica (Mont): Remove rules; no longer needed.
(America/Thunder_Bay): Refer to Toronto rules, not Mont.
This doesn't change any time stamps.
* zone.tab (America/Montreal): Remove.
(America/Toronto): Say that it also covers most of Quebec.
* iso3166.tab (BQ): Change common name to "Caribbean Netherlands".

This appears to be a more common name in English for this newish
political region; for example, see
<http://en.wikipedia.org/wiki/Caribbean_Netherlands>.