added version_added to new feature, removed unused aliases

cloud/google/gce_img.py

@@ -33,57 +33,48 @@ options:
       - the name of the image to create or delete
     required: true
     default: null
-    aliases: []
   description:
     description:
       - an optional description
     required: false
     default: null
-    aliases: []
   source:
     description:
       - the source disk or the Google Cloud Storage URI to create the image from
     required: false
     default: null
-    aliases: []
   state:
     description:
       - desired state of the image
     required: false
     default: "present"
     choices: ["present", "absent"]
-    aliases: []
   zone:
     description:
       - the zone of the disk specified by source
     required: false
     default: "us-central1-a"
-    aliases: []
   timeout:
     description:
       - timeout for the operation
     required: false
     default: 180
-    aliases: []
+    version_added: "2.0"
   service_account_email:
     description:
       - service account email
     required: false
     default: null
-    aliases: []
   pem_file:
     description:
       - path to the pem file associated with the service account email
     required: false
     default: null
-    aliases: []
   project_id:
     description:
       - your GCE project ID
     required: false
     default: null
-    aliases: []
-
 requirements:
     - "python >= 2.6"
     - "apache-libcloud"