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.

not patched

Original patch by Tim Heaney.

Patch by Tim Heaney and Vajrasky Kok.

Patch by Tim Heaney and Vajrasky Kok.

source code.

code.

exists when checking for a package.

Before there was an isdir check and then various isfile checks for
possible __init__ files when looking for a package.
This change drops the isdir check by leaning
on the assumption that a directory will not contain something named
after the module being imported which is not a directory. If the module
is a package then it saves a stat call. If there is nothing in the
directory with the potential package name it also saves a stat call.
Only if there is something in the directory named the same thing as
the potential package will the number of stat calls increase
(due to more wasteful __init__ checks).

Semantically there is no change as the isdir check moved
down so that namespace packages continue to have no chance of
accidentally collecting non-existent directories.