Very basic --diff option for showing what happens when templates change.

Probably output is not useful if not used with --limit

Works well with --check mode

bin/ansible-playbook

@@ -52,8 +52,15 @@ def main(args):
 
     # create parser for CLI options
     usage = "%prog playbook.yml"
-    parser = utils.base_parser(constants=C, usage=usage, connect_opts=True, 
-        runas_opts=True, subset_opts=True, check_opts=True)
+    parser = utils.base_parser(
+        constants=C, 
+        usage=usage, 
+        connect_opts=True, 
+        runas_opts=True, 
+        subset_opts=True, 
+        check_opts=True,
+        diff_opts=True
+    )
     parser.add_option('-e', '--extra-vars', dest="extra_vars", default=None,
         help="set additional key=value variables from the CLI")
     parser.add_option('-t', '--tags', dest='tags', default='all',
@@ -122,7 +129,8 @@ def main(args):
             extra_vars=extra_vars,
             private_key_file=options.private_key_file,
             only_tags=only_tags,
-            check=options.check
+            check=options.check,
+            diff=options.diff
         )
         
         if options.listhosts: