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

MFC r268945:
Fix hdestroy() compliance issue.

The hcreate(3) implementation and related functions we inherited
from NetBSD used to free() the key value, something that is not
supported by the standard implementation.

This would cause a segmentation fault when attempting to run
the examples from the opengroup and linux manpages.

There is no need to bump the __FreeBSD_version as we have
always claimed XPG4.2 compliance but if some reference is
required, the bump for r269484 can be used.

Reference:
http://bugs.dragonflybsd.org/issues/1398

MFC r268644:
libc/stdlib: Minor cleanups to code originating in NetBSD

Mostly ANSIfication and typos.

Obtained from: NetBSD

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

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

- remove superfluous word
- remove contractions

MFC after: 3 days

Remove improper use of <namespace.h>

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

Add new, from scratch implementation of hsearch() et al that actually works.

Obtained from: NetBSD
MFC after: 1 month