add examples for properties and doc build script

* add image property examples for v1 and v2
* add standard sphinx doc build helper

Change-Id: I2f8dff884d9f22cc582aabcbbbbaea6d6fe725c0

doc/source/apiv2.rst

@@ -38,6 +38,18 @@ Update a specific image::
    # update with a list of image attribute names and their new values
    glance.images.update(image.id, name="myNewImageName")
 
+Custom Properties
+-----------------
+Set a custom property on an image::
+
+   # set an arbitrary property on an image
+   glance.images.update(image.id, my_custom_property='value')
+
+Remove a custom property from an image::
+
+   # remove the custom property 'my_custom_property'
+   glance.images.update(image.id, remove_props=['my_custom_property'])
+
 Delete
 ------
 Delete specified image(s)::

doc/source/index.rst

@@ -10,6 +10,7 @@ In order to use the python api directly, you must first obtain an auth token and
     >>> image.update(data=open('/tmp/myimage.iso', 'rb'))
     >>> print image.status
     'active'
+    >>> image.update(properties=dict(my_custom_property='value'))
     >>> with open('/tmp/copyimage.iso', 'wb') as f:
             for chunk in image.data:
                 f.write(chunk)