Cmd used to blindly chop off the last character of every input line.  If
the input reached EOF and there was no final new line, it would truncate
the last character of the last command.  This fix instead strips trailing
\r\n from the input lines.  While this is a small behavior change, it
should not break any working code, since feeding a '\r\n' terminated
file to Cmd would previously leave the \r's on the lines, resulting
in failed command execution.

I wrote the unit test in preparation for a PyOhio TeachMe session
run by Catherine Devlin, and we can thank Catherine and the PyOhio
session attendees for the fix.  I've added Catherine to the Acks file
for organizing and leading the TeachMe session, out of which we will
hopefully get some new contributors.

#8292: Fix three instances of truth tests on return values of filter() (which is always true in Python 3).

at import time, rather by default use the current streams like the
other APIs that output help.

#7909: the prefixes \\.\ and \\?\ indicate special Windows paths, do not try to manipulate them.  See http://msdn.microsoft.com/en-us/library/aa365247%28VS.85%29.aspx for details.

#3788: more tests for http.cookies, now at 95% coverage.  Also bring coding style in the module up to PEP 8, where it does not break backwards compatibility.

#9442: do not document a specific format for sys.version; rather refer to version_info and the platform module.

#9440: Remove borderline test case that fails based on unpredictable conditions such as compiler flags.

I removed the implicit conversion from str to bytes.

Copy Sun-specific inclusion of <alloca.h> from 2.7 maint to trunk; it seems to not have been merged to py3k.