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

Implementing 'fallback' nsswitch source. 'fallback' source is used
when particular function can't be found in nsswitch-module. For
example, getgrouplist(3) will use module-supplied 'getgroupmembership'
function (which can work in an optimal way for such source as LDAP) and
will fall back to the stanard iterate-through-all-groups implementation
otherwise.

PR: ports/114655
Submitted by: Michael Hanselmann <freebsd AT hansmi DOT ch>
Reviewed by: brooks (mentor)

Per Regents of the University of Calfornia letter, remove advertising
clause.

# If I've done so improperly on a file, please let me know.

Cleanup for getgrouplist(3):
- Use /*- instead of /* for copyright section
- Include unistd.h for prototype of it
- Sort and separate includes as described in style(9)
- ANSIfy the function defination
- Use const for the traversing iterator

Eliminate 61 warnings emitted at WARNS=2 (leaving 53 to go).
Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.

Reviewed by: /sbin/md5

Fix a syntax error which causes an annoying warning.

Fix the style of the SCM ID's.
I believe have made all of libc .c's as consistent as possible.

Fixed syntax error in previous commit. It was non-fatal because it was
in conditional code that happens not to be compiled, and because gcc
doesn't complain garbage after #endif by default.

Fixed some style bugs in previous commit, 1.8 and 1.1.

Fix SCM ID's.

Use the proper type (gid_t) for (group)->gr_gid to be orthogonal
with uid_t usage and (user)->pw_uid.

PR: 3242

Fixed merging error. Lite2 fixed premature failure and didn't
touch duplicate group suppression, but the merge blew away our
duplicate group suppression.

The merge also blew away the -Wall cleanup in rev.1.5, but that
was misformatted, so I didn't restore it.

Merge from Lite2:
filesystem include updates, duplicate group suppression, cleanups,
filesystem whiteout support (unionfs), bidir popen().

General -Wall warning cleanup, part I.
Submitted-By: Kent Vander Velden <graphix@iastate.edu>

Minor cleanup, mostly unused vars and missing #includes.

Bruce pointed out, that a misleading warning would be issued
in an (unlikely) border case (maxgroups==1 and the user is on
an /etc/group line for the same group and that group only ...).

Now this case is dealt with as before ...

Protect against duplicate gids in group list (as could be the
result of being a member of some group in both /etc/group and YP).

This commit was generated by cvs2svn to compensate for changes in r1573,
which included commits to RCS files with non-trunk default branches.

BSD 4.4 Lite Lib Sources