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/gtk/textctrl.cpp

@@ -303,7 +303,7 @@ bool wxTextCtrl::LoadFile( const wxString &file )
 
   Clear();
 
-  FILE *fp = NULL;
+  FILE *fp = (FILE*) NULL;
   struct stat statb;
 
   if ((stat ((char*) (const char*) file, &statb) == -1) || (statb.st_mode & S_IFMT) != S_IFREG ||
@@ -358,7 +358,7 @@ bool wxTextCtrl::SaveFile( const wxString &file )
     }
   else
     {
-      char *text = NULL;
+      char *text = (char*) NULL;
       gint len = 0;
 
       if (m_windowStyle & wxTE_MULTILINE)