Changed calling signature of output_for_cli(); started work on 'textui' backend plugin

ipa

@@ -30,7 +30,12 @@ from ipalib import api
 from ipalib.cli import CLI
 
 if __name__ == '__main__':
+    # If we can't explicitly determin the encoding, we assume UTF-8:
+    if sys.stdin.encoding is None:
+        encoding = 'UTF-8'
+    else:
+        encoding = sys.stdin.encoding
     cli = CLI(api,
-        (s.decode('utf-8') for s in sys.argv[1:])
+        (s.decode(encoding) for s in sys.argv[1:])
     )
     sys.exit(cli.run())