codecs.open().

broke backwards compatibility.

such as was shipped with Centos 5 and Mac OS X 10.4.

libffi to 3.0.13.  (i'm not sure if it is needed anymore but see
issue 10309 for details which makes no mention of upstream; this
change is already in 3.3 and 3.4 but may need reapplying to 2.7
as done here)

  in the merge fun from upstream which already had it in 3.0.13.
* Add the missing update to libffi.info.

from unbuffered (0) to buffering (-1) to match the behavior existing code
expects and match the behavior of the subprocess module in Python 2 to avoid
introducing hard to track down bugs.

  two makefile macros SHLIB_SUFFIX and EXT_SUFFIX. SO now has the value of
  SHLIB_SUFFIX again (as in 2.x and 3.1). The SO macro is removed in 3.4.

available when configured at compile time.

This is a partial fix to the issue of servers disconnecting unexpectedly; in
this case the 421 says they are disconnecting, so we close the socket and
return the 421 in the appropriate error context.

Original patch by Mark Sapiro, updated by Kushal Das, with additional
tests by me.