Remove $FreeBSD$: two-line .h pattern

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

spdx: The BSD-2-Clause-FreeBSD identifier is obsolete, drop -FreeBSD

The SPDX folks have obsoleted the BSD-2-Clause-FreeBSD identifier. Catch
up to that fact and revert to their recommended match of BSD-2-Clause.

Discussed with: pfg
MFC After: 3 days
Sponsored by: Netflix

lib: further adoption of SPDX licensing ID tags.

Mainly focus on files that use BSD 2-Clause license, however the tool I
was using mis-identified many licenses so this was mostly a manual - error
prone - task.

The Software Package Data Exchange (SPDX) group provides a specification
to make it easier for automated tools to detect and summarize well known
opensource licenses. We are gradually adopting the specification, noting
that the tags are considered only advisory and do not, in any way,
superceed or replace the license texts.

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.

Teach libmemstat(3) how to extract malloc(9) statistics using kvm(3),
so that libmemstat can be used to view full memory statistics from
kernel core dumps and /dev/mem. This is provided via a new query
function, memstat_kvm_malloc(), which is also automatically invoked
by memstat_kvm_all(). A kvm handle must be passed in.

This will allow malloc(9)-specific code to be removed from vmstat(8).

Add memstat_kvm_uma(), an implementation of a libmemstat(3) query routine
that knows how to extract UMA(9) allocator statistics from a core dump or
live memory image using kvm(3). The caller is expected to provide the
necessary kvm_t handle, which is then used by libmemstat(3).

With these changes, it is trivially straight forward to re-introduce
vmstat -z support on core dumps, which was lost when UMA was introduced.

In the short term, this requires including vm/ include files that are not
intended for extra-kernel use, requiring in turn some ugliness.

Add libmemstat(3), a library for use by debugging and monitoring
applications in tracking kernel memory statistics. It provides an
abstracted interface to uma(9) and malloc(9) statistics, wrapped
around the recently added binary stream sysctls for the allocators.

Using this interface, it is easy to build monitoring tools, query
specific memory types for usage information, etc. Facilities are
provided for binding caller-provided data to memory types,
incremental updates of memory types, and queries that span multiple
allocators.

Support for additional allocators is (relatively) easy to add.

The API for libmemstat(3) will probably change some over time as
consumers are written, and requirements evolve. It is written to
avoid encoding ABIs for data structure layout into consuming
applications for this reason.

MFC after: 1 week