backport tim_one's checkin of

backport tim_one's checkin of
    revision 2.36 of binascii.c

Another stab at SF 576327: zipfile when sizeof(long) == 8
binascii_crc32():  The previous patch forced this to return the same
result across platforms.  This patch deals with that, on a 64-bit box,
the *entry* value may have "unexpected" bits in the high four bytes.

Bugfix candidate.

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More whitespace cleanup related conflict removal... sigh.