Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

libutil: Use O_CLOEXEC for internal file descriptors from open().

Replace index() and rindex() calls with strchr() and strrchr().

The index() and rindex() functions were marked LEGACY in the 2001
revision of POSIX and were subsequently removed from the 2008 revision.
The strchr() and strrchr() functions are part of the C standard.

This makes the source code a lot more consistent, as most of these C
files also call into other str*() routines. In fact, about a dozen
already perform strchr() calls.

Merger of the quota64 project into head.

This joint work of Dag-Erling Smørgrav and myself updates the
FFS quota system to support both traditional 32-bit and new 64-bit
quotas (for those of you who want to put 2+Tb quotas on your users).

By default quotas are not compiled into the kernel. To include them
in your kernel configuration you need to specify:

options QUOTA # Enable FFS quotas

If you are already running with the current 32-bit quotas, they
should continue to work just as they have in the past. If you
wish to convert to using 64-bit quotas, use `quotacheck -c 64';
if you wish to revert from 64-bit quotas back to 32-bit quotas,
use `quotacheck -c 32'.

There is a new library of functions to simplify the use of the
quota system, do `man quotafile' for details. If your application
is currently using the quotactl(2), it is highly recommended that
you convert your application to use the quotafile interface.
Note that existing binaries will continue to work.

Special thanks to John Kozubik of rsync.net for getting me
interested in pursuing 64-bit quota support and for funding
part of my development time on this project.

Debugging nits found while testing the new 64-bit quota code.

Add and document the quota_convert function which converts between the
old 32-bit and the new 64-bit formats.

Minor bugs turned up during conversion of quotacheck.

Add and document new quoat_on and quota_off functions.

Add quota_maxid which returns the maximum user (or group) identifier
in an associated quotafile. Needed by repquota.

Bug fix in quota_read.

Further extend the quotafile API.

Style

Update the quotafile library to manage both active quotas via the
quotactl(2) interface and inactive quotas by accessing the quota
files directly.

Update the edquota program to use this new interface as proof of
concept.

Make hasquota thread safe.

Move hasquota() function to libutil.

Bug fixes found from using these functions in edquota.

WIP