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/PC/bdist_wininst/install.c b/PC/bdist_wininst/install.c
index 6d01ad5..0219a19 100644
--- a/PC/bdist_wininst/install.c
+++ b/PC/bdist_wininst/install.c
@@ -2540,7 +2540,7 @@
     if (!lines)
         return SystemError(0, "Out of memory");
 
-    /* Read the whole logfile, realloacting the buffer */
+    /* Read the whole logfile, reallocating the buffer */
     while (fgets(buffer, sizeof(buffer), logfile)) {
         int len = strlen(buffer);
         /* remove trailing white space */