starmath: Kill unused forward declaration

Change-Id: I03f76aada322a7222795795d32553ae2425092c3
Reviewed-on: https://gerrit.libreoffice.org/32962Reviewed-by: Takeshi Abe <tabe@fixedpoint.jp>
Tested-by: Takeshi Abe <tabe@fixedpoint.jp>

starmath/inc/ElementsDockingWindow.hxx

@@ -29,7 +29,6 @@
 
 class SmDocShell;
 class SmNode;
-class ElementSelectorUIObject;
 
 class SmElement
 {

starmath/inc/document.hxx

@@ -41,7 +41,6 @@
 #include "smmod.hxx"
 #include "smdllapi.hxx"
 
-class SmNode;
 class SfxPrinter;
 class Printer;
 class SmCursor;

starmath/inc/view.hxx

@@ -36,7 +36,6 @@
 #include "edit.hxx"
 #include "node.hxx"
 
-class DataChangedEvent;
 class SmDocShell;
 class SmViewShell;
 class SmPrintUIOptions;

starmath/source/accessibility.hxx

@@ -43,11 +43,6 @@ class SmGraphicWindow;
 class SmEditWindow;
 class SmDocShell;
 
-namespace com { namespace sun { namespace star { namespace accessibility {
-struct AccessibleEventObject;
-}}}}
-
-
 // classes and helper-classes used for accessibility in the graphic-window
 
 

starmath/source/eqnolefilehdr.hxx

@@ -23,9 +23,6 @@
 #include <sal/types.h>
 #include <sot/storage.hxx>
 
-class SotStorageStream;
-class SotStorage;
-
 #define EQNOLEFILEHDR_SIZE 28
 
 class EQNOLEFILEHDR