removed unused forward declarations of class

Change-Id: I9762e198825fbc697f4049a7da5755d72c14e481

dbaccess/source/ui/inc/TablesSingleDlg.hxx

@@ -31,9 +31,6 @@ namespace com { namespace sun { namespace star {
     namespace beans {
         class XPropertySet;
     }
-    namespace sdbc {
-        class XConnection;
-    }
     namespace lang {
         class XMultiServiceFactory;
     }

dbaccess/source/ui/inc/querycontroller.hxx

@@ -50,7 +50,6 @@ namespace comphelper
 namespace dbaui
 {
     class OQueryContainerWindow;
-    class OQueryTableWindow;
 
     class OQueryController;
     typedef ::comphelper::OPropertyContainer                            OQueryController_PBase;

sfx2/source/inc/workwin.hxx

@@ -39,8 +39,6 @@
 #include <sfx2/ctrlitem.hxx>
 #include <sfx2/viewfrm.hxx>
 
-class SfxInPlaceEnv_Impl;
-class SfxPlugInEnv_Impl;
 class SfxSplitWindow;
 class SfxWorkWindow;