view iface: remove more unused methods

GcalView::draw_event overlapped a bit with GcalView::will_add_event, so
the same reasons for removing one stand for the other.
GcalView::clear was a hack for the composited GcalDayView which has
gone, and was a bad experiment.

src/gcal-view.h

@@ -61,9 +61,7 @@ struct _GcalViewIface
   gchar*          (*get_right_header)                   (GcalView     *view);
 
   /* Container functions related API */
-  gboolean        (*draw_event)                         (GcalView *view, icaltimetype *start_date, icaltimetype *end_date);
   GtkWidget*      (*get_by_uuid)                        (GcalView *view, const gchar *uuid);
-  void            (*clear)                              (GcalView *view);
 };
 
 GType         gcal_view_get_type                      (void);
@@ -88,15 +86,9 @@ gchar*        gcal_view_get_left_header               (GcalView     *view);
 
 gchar*        gcal_view_get_right_header              (GcalView     *view);
 
-gboolean      gcal_view_draw_event                    (GcalView     *view,
-                                                       icaltimetype *start_date,
-                                                       icaltimetype *end_date);
-
 GtkWidget*    gcal_view_get_by_uuid                   (GcalView     *view,
                                                        const gchar  *uuid);
 
-void          gcal_view_clear                         (GcalView     *view);
-
 G_END_DECLS
 
 #endif /* __GCAL_MONTH_VIEW_H__ */