MFC r314654:

cddl: normalize paths using SRCTOP-relative paths or :H when possible

This simplifies make logic/output

While here, remove bogus CFLAGS which look for headers in cddl/lib/libumem.
There aren't any source files there (just Makefiles)

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Raise the WARNS level in cddl/lib

cddl/lib/libavl/Makefile
cddl/lib/libctf/Makefile
cddl/lib/libnvpair/Makefile
cddl/lib/libumem/Makefile
cddl/lib/libuutil/Makefile
Increase WARNS to the highest working level for each of these
libraries

Approved by: re (gjb, hrs)
MFC after: 4 weeks
Sponsored by: Spectra Logic Corp

Remove manual .includes in cddl Makefiles

- Break the dependency on ../Makefile.inc for .PATH, and include
../Makefile.inc implicitly. This is required to ...
- Set WARNS?=6 in top-level Makefile.inc
- Remove now redundant WARNS settings, add WARNS?=0 where appropriate
- Remove redundant SHLIB_MAJOR overrides
- Use NO_MAN, not MK_MAN=no
- Remove redundant inclusion of bsd.own.mk
- Order Makefiles more according to style.Makefile(9)
- Reduce diff of cddl Makefiles against each other

No objection: pjd
Approved by: ed (co-mentor)

The sources covered by Sun's CDDL have been repo copied below the
src/cddl and src/sys/cddl directories per the core@ decision following
the license review.

This change modifies the affected Makefiles to reference the sources
in their new location.

Apply a set of style.Makefile(5) changes to src/cddl/ makefiles.
There are some insignificant non-style changes as well.

Not fixed: makefiles use ${LIBTHR} that doesn't exist, thus
breaking "make checkdpadd" and not tracking dependencies
properly.

Approved by: pjd

Please welcome ZFS - The last word in file systems.

ZFS file system was ported from OpenSolaris operating system. The code in under
CDDL license.

I'd like to thank all SUN developers that created this great piece of software.

Supported by: Wheel LTD (http://www.wheel.pl/)
Supported by: The FreeBSD Foundation (http://www.freebsdfoundation.org/)
Supported by: Sentex (http://www.sentex.net/)