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

include/wx/generic/treectrl.h

@@ -456,6 +456,7 @@ protected:
     wxBrush             *m_hilightBrush;
     wxImageList         *m_imageListNormal,
                         *m_imageListState;
+    int                  m_dragCount;
 
     // the common part of all ctors
     void Init();