Fix docstring on novaclient

Something like this:

1. Modify "`Image` to add metadata to" to ""`Image` to delete metadata" on
delete_meta()
2. Modify "The security group to delete" to "The security group to update"
on update()
3. Remove the "password" from the description on update()

Change-Id: I0120d84cc263d4eb58b692a5eb6f20ca0ef8264d
Closes-Bug: #1258461

novaclient/v1_1/images.py

@@ -92,7 +92,7 @@ class ImageManager(base.ManagerWithFind):
         """
         Delete metadata from an image
 
-        :param image: The :class:`Image` to add metadata to
+        :param image: The :class:`Image` to delete metadata
         :param keys: A list of metadata keys to delete from the image
         """
         for k in keys:

novaclient/v1_1/security_groups.py

@@ -52,7 +52,7 @@ class SecurityGroupManager(base.ManagerWithFind):
         """
         Update a security group
 
-        :param group: The security group to delete (group or ID)
+        :param group: The security group to update (group or ID)
         :param name: name for the security group to update
         :param description: description for the security group to update
         :rtype: the security group object

novaclient/v1_1/servers.py

@@ -43,10 +43,9 @@ class Server(base.Resource):
 
     def update(self, name=None):
         """
-        Update the name or the password for this server.
+        Update the name for this server.
 
         :param name: Update the server's name.
-        :param password: Update the root password.
         """
         self.manager.update(self, name=name)