ls(1): Return previous long format for C/POSIX locales

ls(1): Return previous long format for C/POSIX locales

The output of ls -l for POSIX locales is covered by the POSIX standard.
The previous implementation was not compliance with the handling of
future timestamps.  The standard requires that future timestamps always
show the year where as previously it would only show the year if the
file's modification time was less than 6 months into the future.

This change detects if C/POSIX LC_TIME is specified, and if so, it
implements the long format as specified by the POSIX standard.  The
ISO 8601 format is still used for named locales.

Reported by:	swildner