fix all codecs file wrappers to work correctly with the "with"
statement (bug #1586513).

Will backport.

Will backport.

Will backport.

It seems like this should be a different error than SystemError, but
I don't have any great ideas and SystemError was raised in 2.4 and earlier.

Will backport.

it's held (even by the current thread).

Will backport.

loops are, um, infinite.  These conditions should not be able to happen.

Will backport.

some warnings from Klokwork.  They verify the assumptions of the format
of svn version output.

The assert in the thread module helped debug a problem on HP-UX.

I tried to enclose all tests which must be run at the toplevel
(instead of inside a method) in exec statements.

tests.

Will backport to release25-maint.

not the posix error code; with test.
Fixes #1576174.

Will backport to release25-maint.

base64.encodestring() for encoding authentication data.
encodestring() can include newlines for very long input, which
produced broken HTTP headers.

[Bug #1575506] The _singlefileMailbox class was using the wrong file object in its flush() method, causing an error

Point users to the subprocess module in the docs for os.system, os.spawn*, os.popen2, and the popen2 and commands modules

[Bug #1542016] Report PCALL_POP value.  This makes the return value of sys.callstats() match its docstring.

Backport candidate.  Though it's an API change, this is a pretty obscure
portion of the API.

Fixes #1545696 and #1566140. Will backport to 2.5.