Fix a bunch of typos in documentation, docstrings and comments.
(From SF patch #810751)
diff --git a/Lib/heapq.py b/Lib/heapq.py
index fee7a24..2c30b12 100644
--- a/Lib/heapq.py
+++ b/Lib/heapq.py
@@ -238,7 +238,7 @@
         heap[pos] = heap[childpos]
         pos = childpos
         childpos = 2*pos + 1
-    # The leaf at pos is empty now.  Put newitem there, and and bubble it up
+    # The leaf at pos is empty now.  Put newitem there, and bubble it up
     # to its final resting place (by sifting its parents down).
     heap[pos] = newitem
     _siftdown(heap, startpos, pos)