Replace references to "adv" with "core" in classes documentation

All classes previously in "wxadv" are now in "wxcore".

interface/wx/calctrl.h

@@ -40,7 +40,7 @@ enum
 
     The wxCalendarEvent class is used together with wxCalendarCtrl.
 
-    @library{wxadv}
+    @library{wxcore}
     @category{events}
 
     @see wxCalendarCtrl
@@ -90,7 +90,7 @@ enum wxCalendarDateBorder
     wxCalendarDateAttr is a custom attributes for a calendar date. The objects
     of this class are used with wxCalendarCtrl.
 
-    @library{wxadv}
+    @library{wxcore}
     @category{data}
 
     @see wxCalendarCtrl
@@ -296,7 +296,7 @@ enum wxCalendarHitTestResult
     @note Changing the selected date will trigger an EVT_CALENDAR_DAY, MONTH or
           YEAR event as well as an EVT_CALENDAR_SEL_CHANGED event.
 
-    @library{wxadv}
+    @library{wxcore}
     @category{ctrl}
     @appearance{calendarctrl}