The gcal_recurrence_is_equal function checks if two recurrences are
equal or not. When a user is trying to modify the recurrence-rules
of an already recurring event, this function tells us if the
recurrence-dialog should pop up or not.
This patch also removes some unused code.
https://bugzilla.gnome.org/show_bug.cgi?id=782755
Currently, gnome-calendar has no component to deal
with recurrence-rules of events. This missing component
is however required to create and modify recurring events.
This patch adds the required GcalRecurrence component
which parses the recurrence-rules with details like:
* Frequency of the recurring event
* Duration of the recurrences:
** If they repeat until a particular date
** If they repeat a fixed number of times
** If they repeat forever
and then stores these details in a suitable format
in the GcalRecurrence structure. The gcal-recurrence
functions simplify the task of handling and editing
recurrences. This structure is the first step towards
creating a new 'recurrence' property of an event.
https://bugzilla.gnome.org/show_bug.cgi?id=782755