Add ref to usage faq

jenshnielsen · jenshnielsen · commit 31837cc04546 · 2016-06-20T21:26:17.000+01:00
diff --git a/lib/matplotlib/backends/backend_gdk.py b/lib/matplotlib/backends/backend_gdk.py
@@ -438,7 +438,9 @@ def __init__(self, figure):
             warn_deprecated('2.0', message="The GDK backend is "
                             "deprecated. It is untested, known to be "
                             "broken and will be removed in Matplotlib 2.2. "
-                            "Use the Agg backend instead.",
+                            "Use the Agg backend instead. "
+                            "See Matplotlib usage FAQ for"
+                            " more info on backends.",
                             alternative="Agg")
         self._renderer_init()
 
diff --git a/lib/matplotlib/backends/backend_gtk.py b/lib/matplotlib/backends/backend_gtk.py
@@ -217,7 +217,9 @@ def __init__(self, figure):
             warn_deprecated('2.0', message="The GTK backend is "
                             "deprecated. It is untested, known to be "
                             "broken and will be removed in Matplotlib 2.2. "
-                            "Use the GTKAgg backend instead.",
+                            "Use the GTKAgg backend instead. "
+                            "See Matplotlib usage FAQ for"
+                            " more info on backends.",
                             alternative="GTKAgg")
         if _debug: print('FigureCanvasGTK.%s' % fn_name())
         FigureCanvasBase.__init__(self, figure)
diff --git a/lib/matplotlib/backends/backend_wx.py b/lib/matplotlib/backends/backend_wx.py
@@ -192,7 +192,8 @@ def __init__(self, bitmap, dpi):
         warn_deprecated('2.0', message="The WX backend is "
                         "deprecated. It's untested "
                         "and will be removed in Matplotlib 2.2. "
-                        "Use the WXAgg backend instead.",
+                        "Use the WXAgg backend instead. "
+                        "See Matplotlib usage FAQ for more info on backends.",
                         alternative='WXAgg')
         RendererBase.__init__(self)
         DEBUG_MSG("__init__()", 1, self)
