Fix typos in comments, docs and test names (#15018)

* Fix typos in comments, docs and test names

* Update test_pyparse.py

account for change in string length

* Apply suggestion: splitable -> splittable

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Apply suggestion: splitable -> splittable

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Apply suggestion: Dealloccte -> Deallocate

Co-Authored-By: Terry Jan Reedy <tjreedy@udel.edu>

* Update posixmodule checksum.

* Reverse idlelib changes.
diff --git a/Lib/unittest/result.py b/Lib/unittest/result.py
index c7e3206..111317b 100644
--- a/Lib/unittest/result.py
+++ b/Lib/unittest/result.py
@@ -161,7 +161,7 @@
         """Tells whether or not this result was a success."""
         # The hasattr check is for test_result's OldResult test.  That
         # way this method works on objects that lack the attribute.
-        # (where would such result intances come from? old stored pickles?)
+        # (where would such result instances come from? old stored pickles?)
         return ((len(self.failures) == len(self.errors) == 0) and
                 (not hasattr(self, 'unexpectedSuccesses') or
                  len(self.unexpectedSuccesses) == 0))