GcalEditDialog::clear_data was clearing the summary on the internal
ECalComponent instance. Blocking signal handler call allow to clear the
widget without clearing the component.
Bug: https://bugzilla.gnome.org/show_bug.cgi?id=739307
The code added make the dialog show up. Probably anything else works,
but it's start to keep the project building while GcalManager migration
is finished and new GcalEditDialog is built.
Build against gtk+ master without warnings.
Used new GtkHeaderBar as titlebar of the dialog.
Reworked read-only event notification. Show up on the titlebar now.
Hooked signals from date and time entries.
Added comparison and adjustment if the interval.
Removed SimpleDate and SimpleTime structs.
Added _get_end_date for end-date change notification.
Initial support for storing event-data so the EditDialog can
tell which properties has changed.
Changed time entries for GcalTimeEntry objects.
Set ::activates-default property of summary_entry to handle change title
with one keystroke.
Added very initial support to handle obtention of the modified properties
of the edited event. There's still some kind of Model implementation to keep
track of the changes made by the user.
Note: There's still missing one pixel border, I can't find the reason today.
And there's still need to theme better the background of the readonly header.
But the major changes are done.
