Issue #27626: Spelling fixes in docs, comments and internal names

Based on patch by Ville Skyttä.
diff --git a/Lib/test/test_cookielib.py b/Lib/test/test_cookielib.py
index 5182bc0..f2dd972 100644
--- a/Lib/test/test_cookielib.py
+++ b/Lib/test/test_cookielib.py
@@ -346,7 +346,7 @@
 ##   comma-separated list, it'll be a headache to parse (at least my head
 ##   starts hurting every time I think of that code).
 ## - Expires: You'll get all sorts of date formats in the expires,
-##   including emtpy expires attributes ("expires="). Be as flexible as you
+##   including empty expires attributes ("expires="). Be as flexible as you
 ##   can, and certainly don't expect the weekday to be there; if you can't
 ##   parse it, just ignore it and pretend it's a session cookie.
 ## - Domain-matching: Netscape uses the 2-dot rule for _all_ domains, not