dtrace: Add the 'oformat' libdtrace option

This option can be used to specify a format to use in DTrace output.
The following formats are supported:
- json
- xml
- html
- none (default DTrace output)

This is implemented using libxo and integrated into libdtrace. Client
code only works with the following API:

- dtrace_oformat_setup(dtrace_hdl_t *) -- to be called when output is starting.
- dtrace_oformat_teardown(dtrace_hdl_t *) -- to be called when output is finished
- dtrace_oformat(dtrace_hdl_t *) -- check if oformat is enabled.
- dtrace_set_outfp(FILE *) -- sets the output file for oformat.
- Ensure that oformat is correctly checked in the drop handler and record
processing callbacks.

This commit also adds tests which check if the generated output is
valid (JSON, XML) and extends the dtrace(1) describing the structured output.

Reviewed by: markj
Discussed with: phil
MFC after: 2 months
Sponsored by: Innovate UK
Differential Revision: https://reviews.freebsd.org/D41745

Mechanically convert cddl sun #ifdef's to illumos

Since the upstream for cddl code is now illumos not sun, mechanically
convert all sun #ifdef's to illumos #ifdef's which have been used in all
newer code for some time.

Also do a manual pass to correct the use if #ifdef comments as per style(9)
as well as few uses of #if defined(__FreeBSD__) vs #ifndef illumos.

MFC after: 1 month
Sponsored by: Multiplay

In cddl/contrib/opensolaris/lib/libdtrace/common/dt_handle.c, some
uint64_t values are snprintf'd using %llx. On amd64, uint64_t is
typedef'd as unsigned long, so cast the values to u_longlong_t, as is
done similarly in the rest of the file.

MFC after: 1 week

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.

Make this file compile cleanly.