Reviewed by Georg.

Placeholder sentence pointing out that imoprtlib has updated (as well as deprecated) ABCs thanks to the new .pyc situation.

in subprocess.Popen.

Don't try to package subprocessdata/*.py twice.

length and a non-zero offset, and an attempt to read past the end of file
is made (IndexError is raised instead).  Patch by Ross Lagerwall.

Requested by Georg.

PyEval_ReleaseLock().  The thread-state aware APIs should be used instead.