s/it desired/is desired/ in documentation.

Fixes PR lib/59409. From Zhaoming Luo

branches: 1.18.2; 1.18.4;
remove double t from targeted, add missing r to arbitrary
And fix few more typos along the way in comments and man pages.

fix typos in word "successful".

Remove exgtraneous comma

branches: 1.15.2;
Typos.

New sentence, new line.

some minor updates and reality-checks

Use Mt for email addresses.

branches: 1.11.6; 1.11.10;
Add missing Fa macro argument.

branches: 1.10.6;
Update. Especially, describe ukfs_mount_disk(), ukfs_release() flags
and return value, and remove obsolete info in BUGS.

fix markup

Use .Bl -ohang instead of physical markup.

MNT_SOFTDEP -> MNT_LOG in example. pointed out by mrg.

branches: 1.6.2; 1.6.4;
Fix two mdoclint warnings.

Add BUGS section which notes that dynamic linker features in dealing
with link sets prevent from including more than one file system on
the link line and that the rest must be loaded dynamically at runtime.

branches: 1.4.2;
fix type for a few functions

Introduce ukfs_vfstypes() which returns the available file system
types loaded into rump. Now it is possible to iterate over all
file system types supported by a rump program in an attempt to
access an unknown file system image instead of having to know
beforehand which type of file system is on the image.

Support ukfs_modload(), which dlopens and vfs_attaches rump file
system modules for use. Sneakily this solves the problem with the
dynamic linker not wanting to handle the modules link set for
binaries where more than one file system library is included during
the link phase and therefore only one of the file systems getting
vfs_attach()ed in rump "boot". But more importantly, this is really
TRTTD, since now applications can be built, linked and shipped
completely independently of the file systems they support.

tested by Arnaud Ysmal

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