[nautilus-python] Update examples and documentation to recommend always implementing get_backround-items, to avoid war

[Adam Plumb <adamplumb src gnome org>]

commit 0759bbe7595e4ce2966a3d47734626b2a42044a5
Author: Adam Plumb <adamplumb gmail com>
Date:   Wed Dec 6 19:14:31 2017 -0500

    Update examples and documentation to recommend always implementing get_backround-items, to avoid warnings

 docs/reference/entities.docbook                    |    1 +
 .../reference/nautilus-python-overview-example.xml |    7 ++++++-
 examples/background-image.py                       |    5 +++++
 examples/open-terminal.py                          |   10 ++++++----
 4 files changed, 18 insertions(+), 5 deletions(-)
---
diff --git a/docs/reference/entities.docbook b/docs/reference/entities.docbook
new file mode 100644
index 0000000..d5bd714
--- /dev/null
+++ b/docs/reference/entities.docbook
@@ -0,0 +1 @@
+<!ENTITY version "1.1">
diff --git a/docs/reference/nautilus-python-overview-example.xml 
b/docs/reference/nautilus-python-overview-example.xml
index c2908eb..2efa71f 100644
--- a/docs/reference/nautilus-python-overview-example.xml
+++ b/docs/reference/nautilus-python-overview-example.xml
@@ -33,7 +33,12 @@ class ColumnExtension(GObject.GObject, Nautilus.MenuProvider):
         )
         item.connect('activate', self.menu_activate_cb, file)
         
-        return [item]</programlisting>
+        return [item]
+        
+    # Even though we're not using background items, Nautilus will generate
+    # a warning if the method isn't present
+    def get_background_items(self, window, file):
+        return None</programlisting>
     </example>
     
     <para>Save this file as TestExtension.py in the ~/.local/share/nautilus-python/extensions folder. 
diff --git a/examples/background-image.py b/examples/background-image.py
index 535ec8d..f5fca3c 100644
--- a/examples/background-image.py
+++ b/examples/background-image.py
@@ -34,3 +34,8 @@ class BackgroundImageExtension(GObject.GObject, Nautilus.MenuProvider):
                                  tip='Set the current image as a background image')
         item.connect('activate', self.menu_activate_cb, file)
         return item,
+
+    # Current versions of Nautilus will throw a warning if get_background_items
+    # isn't present
+    def get_background_items(self, window, file):
+        return None
diff --git a/examples/open-terminal.py b/examples/open-terminal.py
index 7c70844..448bc94 100644
--- a/examples/open-terminal.py
+++ b/examples/open-terminal.py
@@ -2,6 +2,8 @@
 import os
 import urllib
 
+import gi
+gi.require_version('GConf', '2.0')
 from gi.repository import Nautilus, GObject, GConf
 
 TERMINAL_KEY = '/desktop/gnome/applications/terminal/exec'
@@ -32,14 +34,14 @@ class OpenTerminalExtension(Nautilus.MenuProvider, GObject.GObject):
             return
         
         item = Nautilus.MenuItem(name='NautilusPython::openterminal_file_item',
-                                 label='Open Terminal' ,
+                                 label='Open Terminal 2' ,
                                  tip='Open Terminal In %s' % file.get_name())
         item.connect('activate', self.menu_activate_cb, file)
         return item,
 
     def get_background_items(self, window, file):
-        item = Nautilus.MenuItem(name='NautilusPython::openterminal_item',
-                                 label='Open Terminal Here',
-                                 tip='Open Terminal In This Directory')
+        item = Nautilus.MenuItem(name='NautilusPython::openterminal_file_item2',
+                                 label='Open Terminal BG' ,
+                                 tip='Open Terminal In %s' % file.get_name())
         item.connect('activate', self.menu_background_activate_cb, file)
         return item,