This should supersede revision e3ec6b17260c (but please test before removing that).

Patch by David Edelsohn.

Patch by David Edelsohn.

by Steven D'Aprano.

See http://bugs.python.org/issue19293

See http://bugs.python.org/issue19295

- explain single use, reusable and reentrant in docs
- converted suppress to a reentrant class based impl
- converted redirect_stdout to a reusable impl
- moved both suppress and redirect_stdout behind a functional
  facade
- added reentrancy tests for the updated suppress
- added reusability tests for the updated redirect_stdio
- slightly cleaned up an exception from contextmanager

for C files to generate argument parsing code.  (See PEP 436.)

of OPT for special build options.  By setting OPT, some compiler-specific
options like -fwrapv were overridden and thus not used, which could result
in broken interpreters when building with clang.

    1. ppc arch detection for extension module builds broke with Xcode 5
    2. ppc arch detection in configure did not work on OS X 10.4
    3. -sysroot and -arch flags were unnecessarily duplicated
    4. there was no obvious way to configure an intel-32 only build.