'RELENG_2_2_8_RELEASE'.

This commit was manufactured to restore the state of the 2.2.8-RELEASE image.
Releases prior to 5.3-RELEASE are omitting the secure/ and crypto/ subdirs.

configurable fallback search paths, as well as new crt interface version.

Also:
 - even faster getenv(), get all environment variable settings in a single
   pass.
 - ldd printf-like format specifications
 - minor code cleanups, one vsprintf -> vsnprintf (harmless)

The library search sequence is a little more complete now. Before,
it'd search $LD_LIBRARY_PATH (by opendir/readdir/closedir), then read
the hints file, then read /usr/lib (again by scanning thr directory).  It
would then fail if there was no "found" library.

Now, it does LD_LIBRARY_PATH and the hints file the same, but then uses
a longer fallback path.  The -R path is fetched from the executable if
specified at build time, the ldconfig path is appended, and /usr/lib is
appended to that. Duplicates are suppressed.  This means that simply
placing a new library in /usr/local/lib will work (the same as it did in
/usr/lib) without needing ldconfig -m.  It will find it quicker if the
ldconfig is run though.

Similar changes have been made to the NetBSD ld.so, but ours is rather
different now due to John Polstra's speedups and fixes from a while back.

The ldd printf-like format support came direct from NetBSD.

Reviewed by: nate, jdp

as atomically as possible.

(Immutable targets can't be renamed without opening a window when
neither the source nor the target is immutable.  Perhaps there
should be a rename_immutable syscall to do this if unsetting the
immutable flags would work.)

``rm'' -> ``rm -f''
so mv/rm may not ask for confirmation if you are not root

doesn't fall over.

Obtained from:	NetBSD

NetBSD ld code except for local changes for dlopen() and friends and
the hashing on the minor value of the shlibs.  We should be binary
compatible now with all their libraries.

Obtained from: NetBSD