Enable creation of static userspace probes in incremental builds.

To define USDT probes, dtrace -G makes use of relocations for undefined
symbols: the target address is overwritten with NOPs and the location is
recorded in the DOF section of the output object file. To avoid link
errors, the original relocation is destroyed. However, this means that
the same input object file cannot be processed multiple times, as
happens during incremental rebuilds. Instead, only set the relocation
type to NONE, so that all information required to reconstruct USDT
probes is preserved.

Reported by: bdrewery
MFC after: 3 weeks
Sponsored by: The FreeBSD Foundation

Fix memory leaks in error cases in libdtrace.

Submitted by: Tom Rix <trix@juniper.net>
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D9705

libdtrace: use calloc(3) instead of malloc(3) when it makes sense.

calloc(3) is faster and occasionally safer than malloc(3) + bzero(3).

In one case, pointed out by Mark[1], this also cleans up a calculation.

Reviewed by: markj [1]
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.