This patch replaces all homegrown timezone
stuff with standard PHP date/time code.
The main change is the introduction of core_date
class that returns normalised user and server
timezones. From now on nobody should be using
$CFG->timezone or $user->timezone directly!
Other new features and fixes:
* admins are prompted for timezone during install
* editing of other users is finally fixed
* timezones are displayed in user profile
* new $this->setTimezone() in phpunit
* time locale is now automatically reset in phpunit
* timezone is now automatically reset in phpunit
* phpunit has Australia/Perth as default timezone
Now MUC is used to cache subscription information when the constructor for an event is called, which is child of a ical subscription.
A new setting calendar_showicalsource is introduced which controls if the ical source should be displayed along with events in the calendar
Also minor changes has been done in places to make sure subscription id is always associated with ical events
