Fix SF # 635969, No error "not all arguments converted"

When mwh added extended slicing, strings and unicode became mappings.
Thus, dict was set which prevented an error when doing:
	newstr = 'format without a percent' % string_value

This fix raises an exception again when there are no formats
and % with a string value.
diff --git a/Lib/test/test_format.py b/Lib/test/test_format.py
index b40e820..da4d85a 100644
--- a/Lib/test/test_format.py
+++ b/Lib/test/test_format.py
@@ -221,6 +221,14 @@
 
 test_exc('%d', '1', TypeError, "int argument required")
 test_exc('%g', '1', TypeError, "float argument required")
+test_exc('no format', '1', TypeError, 
+         "not all arguments converted during string formatting")
+test_exc('no format', u'1', TypeError, 
+         "not all arguments converted during string formatting")
+test_exc(u'no format', '1', TypeError, 
+         "not all arguments converted during string formatting")
+test_exc(u'no format', u'1', TypeError, 
+         "not all arguments converted during string formatting")
 
 if sys.maxint == 2**32-1:
     # crashes 2.2.1 and earlier: