Fix a bunch of typos in documentation, docstrings and comments.

(From SF patch #810751)

cmd.py

@@ -148,7 +148,7 @@ class Command:
         """Set final values for all the options that this command supports.
         This is always called as late as possible, ie.  after any option
         assignments from the command-line or from other commands have been
-        done.  Thus, this is the place to to code option dependencies: if
+        done.  Thus, this is the place to code option dependencies: if
         'foo' depends on 'bar', then it is safe to set 'foo' from 'bar' as
         long as 'foo' still has the same value it was assigned in
         'initialize_options()'.