Remove $FreeBSD$: two-line .h pattern

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

Use tabs in io.d, fix alignment issues, remove extraneous newlines

Unlike Solaris, in FreeBSD p_args can be 0 so check for that
instead of walking down to ar_args blindly.

Reported by: Amanda Strnad
Reviewed by: markj, jhb
MFC after: 2 weeks
Sponsored by: DARPA, AFRL

- Use an explicit "depends_on module kernel" guard in DTrace libraries that
reference types defined in the kernel. Otherwise dtrace(1) expects to find
CTF definitions for all referenced types, which is not very reasonable
when it is being used in a build environment. This was previously worked
around by adding "-x nolibs" to dtrace -h or -G invocations, but as of
r283025, dtrace(1) actually handles dependencies properly, so this is no
longer necessary.
- Remove "pragma ident" directives from DTrace libraries, as they're being
phased out upstream as well.

Submitted by: Krister Johansen <Krister.Johansen@isilon.com> [1]
MFC after: 1 week
Sponsored by: EMC / Isilon Storage Division

Add a function, memstr, which can be used to convert a buffer of
null-separated strings to a single string. This can be used to print the
full arguments of a process using execsnoop (from the DTrace toolkit) or
with the following one-liner:

dtrace -n 'syscall::execve:return {trace(curpsinfo->pr_psargs);}'

Note that this relies on the process arguments being cached via the struct
proc, which means that it will not work for argvs longer than
kern.ps_arg_cache_limit. However, the following rather non-portable
script can be used to extract any argv at exec time:

fbt::kern_execve:entry
{
printf("%s", memstr(args[1]->begin_argv, ' ',
args[1]->begin_envv - args[1]->begin_argv));
}

The debug.dtrace.memstr_max sysctl limits the maximum argument size to
memstr(). Thanks to Brendan Gregg for helpful comments on freebsd-dtrace.

Tested by: Fabian Keil (earlier version)
MFC after: 2 weeks

Finish porting execsnoop to FreeBSD. This includes replacing the zonename
with a jail ID and removing the project ID from the list of options.

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

Create the altix project branch. The altix project will add support
for the SGI Altix 350 to FreeBSD/ia64. The hardware used for porting
is a two-module system, consisting of a base compute module and a
CPU expansion module. SGI's NUMAFlex architecture can be an excellent
platform to test CPU affinity and NUMA-aware features in FreeBSD.

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

Add the DTrace libraries and D library scripts.