manager: Move GcalClock to GcalApplication

GcalManager is basically an object that is shared
among classes that need to modify calendars, while
GcalClock is just a wall clock implementation.

Move it to GcalApplication, so that objects without
access to GcalManager can still access the clock.

src/views/gcal-month-view.c

@@ -21,6 +21,8 @@
 
 #include "config.h"
 #include "e-cal-data-model-subscriber.h"
+#include "gcal-application.h"
+#include "gcal-clock.h"
 #include "gcal-debug.h"
 #include "gcal-month-cell.h"
 #include "gcal-month-popover.h"
@@ -2087,11 +2089,6 @@ gcal_month_view_set_property (GObject       *object,
     case PROP_MANAGER:
       self->manager = g_value_dup_object (value);
 
-      g_signal_connect_swapped (gcal_manager_get_clock (self->manager),
-                                "day-changed",
-                                G_CALLBACK (update_month_cells),
-                                self);
-
       for (i = 0; i < 42; i++)
         gcal_month_cell_set_manager (GCAL_MONTH_CELL (self->month_cell[i / 7][i % 7]), self->manager);
 
@@ -2220,6 +2217,8 @@ gcal_month_view_class_init (GcalMonthViewClass *klass)
 static void
 gcal_month_view_init (GcalMonthView *self)
 {
+  GcalApplication *application;
+
   gtk_widget_init_template (GTK_WIDGET (self));
 
   gtk_widget_set_has_window (GTK_WIDGET (self), FALSE);
@@ -2254,5 +2253,17 @@ gcal_month_view_init (GcalMonthView *self)
                           G_BINDING_DEFAULT);
 
   g_signal_connect (self->overflow_popover, "event-activated", G_CALLBACK (on_month_popover_event_activated_cb), self);
+
+
+  /* Connect to the wall clock */
+  application = GCAL_APPLICATION (g_application_get_default ());
+
+  g_assert (application != NULL);
+
+  g_signal_connect_object (gcal_application_get_clock (application),
+                           "day-changed",
+                           G_CALLBACK (update_month_cells),
+                           self,
+                           G_CONNECT_SWAPPED);
 }