Remove test_doctest's expected-output file.
Change test_doctest and test_difflib to pass regrtest's notion of
verbosity on to doctest.
Add explanation for a dozen "new" things to test/README.
diff --git a/Lib/test/test_doctest.py b/Lib/test/test_doctest.py
index 90a55db..00c0928 100644
--- a/Lib/test/test_doctest.py
+++ b/Lib/test/test_doctest.py
@@ -1,2 +1,3 @@
+from test_support import verbose
 import doctest
-doctest.testmod(doctest, verbose=1)
+doctest.testmod(doctest, verbose=verbose)