Implemented MSW's paint region clipping, but

it exposed some bug in GTK's guffaw stuff.
  Implmented GC pooling.
  Implemented Corrcet mixing of pain region clipping,
    user clipping and masked bitmap clipping.
  Minor other corrections.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@6172 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/generic/plot.cpp

@@ -196,8 +196,6 @@ void wxPlotArea::DrawCurve( wxDC *dc, wxPlotCurve *curve, int from, int to )
     if (to == -1)
         to = view_x + client_width;
         
-    to += 2;  // no idea why this is needed
-
     double zoom = m_owner->GetZoom();
 
     int start_x = wxMax( from, (int)floor(curve->GetStartX()*zoom) );
@@ -206,6 +204,8 @@ void wxPlotArea::DrawCurve( wxDC *dc, wxPlotCurve *curve, int from, int to )
     start_x = wxMax( view_x, start_x );
     end_x = wxMin( view_x + client_width, end_x );
     
+    end_x++;
+
     double double_client_height = (double)client_height;
     double range = curve->GetEndY() - curve->GetStartY();
     double end = curve->GetEndY();