Log Message:
Update to john-1.7.2 and enable per-arch optimization for NetBSD and
OpenBSD.

Changes:
The following changes have been made between John 1.7.1 and 1.7.2:

* Bitslice DES assembly code for x86-64 making use of the 64-bit mode
extended SSE2 with 16 XMM registers has been added for better performance
at DES-based crypt(3) hashes with x86-64 builds on AMD processors.
* New make target for FreeBSD/x86-64.

The following changes have been made between John 1.7.0.2 and 1.7.1:

* Bitslice DES code for x86 with SSE2 has been added for better performance
at DES-based crypt(3) hashes on Pentium 4 and SSE2-capable AMD processors.
* Assorted high-level changes have been applied to improve performance
on current x86-64 processors.
* New make target for NetBSD/SPARC64.
* Minor source code cleanups.