SF bug #623669: only try (e.g.) __rdiv__ before __div__ if the right
class actually overrides it.

a single character.  Shaves another 10% off the running time by avoiding
the lg2(N) loops and cache effects for the other cases.

tests are run.  (All tests in this module should have one of these at
the top.)

* reformat schemes to 80 columns

notes.

vile abomination and should be eradicated!

- give subsection pages nicer names
- shorten some really long table cells; table cells can't wrap in the
  typeset version of the documentation

Document constants for permission bits.

    (Power Macintosh -> Power_Macintosh)

The attached patch enables shared extension
modules to build cleanly under Cygwin without
moving the static initialization of certain function
pointers (i.e., ones exported from the Python
DLL core) to a module initialization function.

Additionally, this patch fixes the modules that
have been changed in the past to accommodate
Cygwin.

Christian Tismer pointed out the high cost of the loop overhead and
function call overhead for 'c' * n where n is large.  Accordingly,
the new code only makes lg2(n) loops.

Interestingly, 'c' * 1000 * 1000 ran a bit faster with old code.  At some
point, the loop and function call overhead became cheaper than invalidating
the cache with lengthy memcpys.  But for more typical sizes of n, the new
code runs much faster and for larger values of n it runs only a bit slower.

- improved readability of rmtree; removed silly apply()

Adding try/except allows the test to pass

localtime()/gmtime() insists on delivering them, + associated doc
changes.

Redid the docs for datetimtez.astimezone().

(backport candidate?)

The range of u=random() is [0,1), so log(u) and 1/x can fail.
Fix by setting u=1-random() or by reselecting for a usable value.

Will backport.

Check whether self is NULL in mainloop.