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/gcal-application.h

@@ -20,6 +20,7 @@
 #ifndef _GCAL_APPLICATION_H_
 #define _GCAL_APPLICATION_H_
 
+#include "gcal-clock.h"
 #include "gcal-weather-service.h"
 #include "gcal-manager.h"
 
@@ -43,6 +44,8 @@ void                 gcal_application_set_uuid                   (GcalApplicatio
 void                 gcal_application_set_initial_date           (GcalApplication    *self,
                                                                   GDateTime          *initial_date);
 
+GcalClock*           gcal_application_get_clock                  (GcalApplication    *self);
+
 G_END_DECLS
 
 #endif /* _GCAL_APPLICATION_H_ */