minor Configure / makefiles updates

Removed mor (egcs) warnings
  Updated version to 2.0.1 in version.h
  Several corrections for strict compilers
  OpenGL updates
  new wxApp::InitVisual() for overriding in order to set non-default visual
    (unportable, of course)
  Added makefiles for DialogEd and Tex2Rtf
  made wxGTK compile with Tex2Rtf
  Added BEGIN_DRAG event to tree ctrl
  Added missing #include to lexel.l (unistd.h) (MSW?)
  new wxGTK.spec
  turned one or two more #ifdef into #if


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@1349 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/gtk1/notebook.cpp

@@ -429,7 +429,7 @@ bool wxNotebook::SetPageImage( int page, int image )
     if (image == -1 && nb_page->m_image == -1)
         return TRUE; /* Case 1): Nothing to do. */
  
-    GtkWidget *pixmapwid = NULL;
+    GtkWidget *pixmapwid = (GtkWidget*) NULL;
  
     if (nb_page->m_image != -1) 
     {