Relying on invariant strings is a mistake. Not only UTF-8, but also
many charsets are not single byte. Actual date formats can be mixed
with arbitrary strings, and this can bring erroneous results in the
out. Thus, instead it is more convenient to say, that a format string
can consist either on UTF-8 or on pure ASCII as its subset. This is
what is currently being done in other classes like Formatter, etc.
as well.
To better support IntlCalendar, added this function:
string IntlDateFormatter::formatObject(IntlCalendar|DateTime $obj [,
array|int|string $format = null [, string $locale = null).
$format is either of the constants IntlDateFormatter::FULL, etc., in
which case this format applies to both the date and the time, an array
in the form array($dateFormat, $timeFormat), or a string with the
SimpleDateFormat pattern.
This uses both the Calendar type and the timezone of the passed object
to configure the formatter (a GregorianCalendar is forced for
DateTime).
Some stuff was moved around and slighlt modified to allow for more code
reuse.
