zic(8): Sync with tzcode2010n from elsie.nci.nih.gov
* Conditionally output extra types with most-recently-used offsets last
(for use by systems with pre-2011 versions of localtime.c, helping to
ensure that globals "altzone" and "timezone" get set correctly).
* Fix generation of POSIX strings for zones with rules using
"weekday<=n" forms of dates (thanks to Lei Liu for finding the
problem). Also, limit output for non-POSIX-specificable zones defined
to follow the same rules every year. (Note that no zones of either of
the above types appear in the distribution; these changes cater to
add-on zones).