Cleanup whitespace.
Fix unbalanced parenthesis.

docs.  Replaced it with an XXX block, because the hoped-for treatment
of DST endcases remains unclear (Guido doesn't really like raising an
exception when it's impossible to deliver a correct result, but so
far I have no way in hand to consistently deliver a defined incorrect
result either).

we'll simply revert to \mailheader since there's no other good name.

- some minor cleanups

Fix a curly brace that should have been a paren.

Add some times

Document that getatime and getmtime may return floats.

 - add new modules (zipimport, datetime, _random, bz2, _symtable)
 - build pyexpat with expat sources from Python distribution
 - regression test with and without compiled bytecode

- whitespace normalization

convenience functions isreadable() and isrecursive() work the same way
as the convenience functions.

    Pass the right number of args to .format().  (Caught by
    pychecker.)
- Protect the global namespace more carefully.
- Don't use the types module now that we don't need to.

when expected.  Only applies to the ConfigParser and SafeConfigParser
classes, not RawConfigParser.

    InterpolationError constructor, not the KeyError exception itself.
    (Caught by the new InterpolationError test.)

SafeConfigParser._interpolate_some():  Pass the right number of
    arguments to the InterpolationError constructor.
    (Caught by pychecker.)