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
Rather than overloading the $CFG->bloglevel setting which had a
confusing UI in the appearance subsystem.
In order to achieve this we modify take the defaults from the existing
bloglevel setting and set that for $CFG->enableblogs. Note that in order
to prevent a bad default settings from being set we also set
$CFG->bloglevel to a valid 'enabled' setting.