remove GCC_NO_ADDR_OF_PACKED_MEMBER for several subdir builds
that are now handled by lfs_accessors.h internally.

add support for new GCC 9 warnings that may be too much to fix
right now. new address-of-packed-member and format-overflow
warnings have new GCC_NO_ADDR_OF_PACKED_MEMBER amd
GCC_NO_FORMAT_OVERFLOW variables to remove these warnings.

apply to a bunch of the tree. mostly, these are real bugs that
should be fixed, but in many cases, only by removing the 'packed'
attribute from some structure that doesn't really need it. (i
looked at many different ones, and while perhaps 60-80% were
already properly aligned, it wasn't clear to me that the uses
were always coming from sane data vs network alignment, so it
doesn't seem safe to remove packed without careful research for
each affect struct.) clang already warned (and was not erroring)
for many of these cases, but gcc picked up dozens more.

Make the abs() use check non-fatal for a bogus use in the LFS cleanerd.

branches: 1.9.2;
Disable default build of debugging info.

branches: 1.8.6;
Define concept "disk based file system" and flag appropriate file
systems as such.

Link fs components into binary instead of loading dynamically now
that it's possible (dependency handling changes to rumpuser_dl).

run lfs cleaner

Make rump_lfs work again: load fs components dynamically instead
of trying to link them in on the command line and get pounded by
link set failage.

Merge librumpfs_ufs into librumpfs_ffs. This reflects what happened
with the ffs kernel module and follows the trend of retiring ufs.
It also allows to get rid of a special case kludge in runtime module
loading, since ufs was not really a module. librumpfs_ufs is now
obsoleted and ffs consumers should be linked solely against
librumpfs_ffs.

branches: 1.3.2;
Link self-contained file systems (i.e. do not depend on other file
systems) against the kernel module on select archs.

branches: 1.2.2;
Refactor mount utilities to provide a mount_fs_parseargs() routine.
Use this routine both in mount_fs and rump_fs to provide equivalent
command line parameters and therefore usage interchangeability.
While doing this, combine some common mountgoop to mountprog.h

Install rump libraries and utilities to the base system and remove the
private non-installed build infrastructure from sys/rump.

breakdown of commit:
* install relevant headers into /usr/include/rump
* build sys/rump/librump/rumpuser and sys/rump/librump/rumpkern
from src/lib and install as librumpuser and librump, respectively
+ this retains the ability to test a librump build with just the
kernel sources at hand
* move sys/rump/fs/lib/libukfs and sys/rump/fs/lib/libp2k to src/lib
for general consumption, they are not kernel-space dwellers anyway
* build and install sys/rump/fs/lib/lib$fs as librumpfs_$fs
* add chapter 3 manual pages for rump, rumpuser, ukfs and p2k
* build and install userspace kernel file system daemons if MKPUFFS=yes
is spexified
* retire fsconsole for now, it will make a comeback with an actually
implemented version shortly