sys: Remove $FreeBSD$: two-line .h pattern

Remove /^\s*\*\n \*\s+\$FreeBSD\$$\n/

Remove ia64.

This includes:
o All directories named *ia64*
o All files named *ia64*
o All ia64-specific code guarded by __ia64__
o All ia64-specific makefile logic
o Mention of ia64 in comments and documentation

This excludes:
o Everything under contrib/
o Everything under crypto/
o sys/xen/interface
o sys/sys/elf_common.h

Discussed at: BSDcan

Add an #include guard to the sys/fnv_hash.h.

MFC after: 3 days

A new jail(8) with a configuration file, to replace the work currently done
by /etc/rc.d/jail.

- Import the HEAD csup code which is the basis for the cvsmode work.

/* -> /*- for license, minor formatting changes

Use the same API as the example code.
Allow the initial hash value to be passed in, as the examples do.
Incrementally hash in the dvp->v_id (using the official api) rather than
add it. This seems to help power-of-two predictable filename trees
where the filenames repeat on a power-of-two cycle and the directory trees
have power-of-two components in it. The simple add then mask was causing
things like 12000+ entry collision chains while most other entries have
between 0 and 3 entries each. This way seems to improve things.

Use a generic implementation of the Fowler/Noll/Vo hash (FNV hash).
Make the name cache hash as well as the nfsnode hash use it.

As a special tweak, create an unsigned version of register_t. This allows
us to use a special tweak for the 64 bit versions that significantly
speeds up the i386 version (ie: int64 XOR int64 is slower than int64
XOR int32).

The code layout is a little strange for the string function, but I was
able to get between 5 to 10% improvement over the original version I
started with. The layout affects gcc code generation choices and this way
was fastest on x86 and alpha.

Note that 'CPUTYPE=p3' etc makes a fair difference to this. It is
around 45% faster with -march=pentiumpro on a p6 cpu.