config.{guess,sub}. Don't use uname calls for cross builds.

This allows generators that are using yield from to be seen by debuggers. It
also kills the f_yieldfrom field on frame objects.

Patch mostly from Mark Shannon with a few tweaks by me.

  config.{guess,sub}.

port from 3.2 - Fix the urllib closing issue which hangs on particular ftp urls/ftp servers. closes issue11199

when configured with --(en|dis)able-ipv6 for cross builds, don't fail the configury due to the missing buggy-getaddrinfo check.

when configured --with(out)-computed-gotos for a cross, use this value instead of defaulting to no.

when using gcc, use a compilation test for the cross build check for long long format.

(sched) when run() is invoked with blocking=False return the deadline of the next scheduled call in the scheduler; this use case was suggested in http://bugs.python.org/issue1641#msg149453

Patch by Dylan Sarber.

(Not sure why hg told me it merged pyexpat.c too, it showed no changes)

Patch by Dylan Sarber.

Issue #13248:  Removed docs for two deprecated unittest features.  To be conservative, the code is left in for one more release.

using --with-system-expat working when the system expat does not have
salted hash support.

using --with-system-expat working when the system expat does not have
salted hash support.

timeout in queue and threading modules to not be affected of system time
update.

 * On Mac OS X, time.steady() now uses mach_absolute_time(), a monotonic clock
 * Optimistic change: bet that CLOCK_MONOTONIC and CLOCK_REALTIME are available
   when clock_gettime() is available
 * Rewrite time.steady() documentation