Added a couple of const to == and != operators.

Removed no-flicker hack which seems to be a
   problem on Sun.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_2_BRANCH@7415 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk1/pen.cpp

@@ -100,12 +100,12 @@ wxPen& wxPen::operator = ( const wxPen& pen )
     return *this;
 }
 
-bool wxPen::operator == ( const wxPen& pen )
+bool wxPen::operator == ( const wxPen& pen ) const
 {
     return m_refData == pen.m_refData;
 }
 
-bool wxPen::operator != ( const wxPen& pen )
+bool wxPen::operator != ( const wxPen& pen ) const
 {
     return m_refData != pen.m_refData;
 }