These directories default to WARNS?=5

Quota-related docs fixes:

- Remove old quotactl(2); replace with new __quotactl(2).
- Document quota_getrestrictions(3), the semantic restriction codes,
and quota_quotaon/off(3).
- Update VFS_QUOTACTL(9), which was still describing the pre-proplib API.

Approved by releng for the freeze.

Remove old (5.99.48 - 5.99.62) libquota interface.

Change the syscall API for quotas over to the new non-proplib one.

- struct vfs_quotactl_args -> struct quotactl_args
- add sys/stdint.h to sys/quotactl.h for clean userland build
- install sys/quotactl.h in /usr/include
- update set lists for same
- add new marshalling code in libquota
- add new unmarshalling code in vfs_syscalls.c
- discard proplib interpreter code in vfs_quotactl.c
- add dispatching code for the 14 quotactl ops in vfs_quotactl.c
- mark the proplib quotactl syscall obsolete
- add a new syscall number for the new quotactl syscall
- change the name of the syscall to __quotactl()
- remove the decl of the old quotactl from quota/quotaprop.h
- add a decl of the new quotactl to sys/quotactl.h
- update the libc build
- update ktruss
- remove proplib marshalling code from libquota
- update copy of syscall table in gdb ppc sources
- hack rumphijack to accomodate new quotactl name (as I recall,
pooka wanted such a name change to simplify something, but I
don't really see what/how)

This change appears to require a kernel version bump for rumpish
reasons.

Add a preliminary man page for libquota.

Implement fallback direct access to quota1-type quota files.
Uses (mostly) code from repquota. Add some missing pieces that
weren't in repquota.

Use the direct file access code for cursors if proplib reports the
quota version is 1.

Add quota_nfs.c and implement quota_get() for nfs, using
code from getnfsquota().

Also implement quota_getmountdevice().

Add initial versions of quota_open(), quota_close(), quota_get(),
calling proplib code mostly taken from getufsquota().

Correct the proplib refcount handling in the code from getufsquota(),
where it was (as far as I can tell) wrong.

Avoid doing illegal and unsafe casts from (struct quotaval *)
to (uint64_t *).

Add stub entry points of the entire new quota interface. These fail or
do nothing for the time being; however, putting them all in up front
avoids the need to do multiple bumps of the libquota.so version.

branches: 1.1.4;
Add a new libquota library, which contains some blocks to build and/or
parse quota plists; as well as a getfsquota() function to retrieve quotas
for a single id from a single filesystem (whatever filesystem this is:
a local quota-enabled fs or NFS). This is build on functions getufsquota()
(for local filesystems with UFS-like quotas) and getnfsquota();
which are also available to userland programs.
move functions from quota2_subr.c to libquota or libprop as appropriate,
and ajust in-tree quota tools.
move some declarations from kernel headers to either sys/quota.h or
quota/quota.h as appropriate. ufs/ufs/quota.h still installed because
it's needed by other installed ufs headers.
ufs/ufs/quota1.h still installed as a quick&dirty way to get a code
using the old quotactl() to compile (just include ufs/ufs/quota1.h instead of
ufs/ufs/quota.h - old code won't compile without this change and this is
on purpose).
Discussed on tech-kern@ and tech-net@ (long thread, but not much about
libquota itself ...)