Fix strcasecmp_l() and strncasecmp_l() POSIX 2008 compliance.

POSIX.1-2008 specifies that those two functions should be declared by
including <strings.h>, not <string.h> (the latter only has strcoll_l()
and strxfrm_l()):

http://pubs.opengroup.org/onlinepubs/9699919799/functions/strcasecmp.html

Obtained from:	DragonFlyBSD
Reviewed by:	theraven
MFC after:	2 weeks

include/strings.h

@@ -59,6 +59,10 @@ char	*rindex(const char *, int) __pure;			/* LEGACY */
 #endif
 int	 strcasecmp(const char *, const char *) __pure;
 int	 strncasecmp(const char *, const char *, size_t) __pure;
+
+#if __POSIX_VISIBLE >= 200809 || defined(_XLOCALE_H_)
+#include <xlocale/_strings.h>
+#endif
 __END_DECLS
 
 #endif /* _STRINGS_H_ */

include/xlocale/Makefile

@@ -2,7 +2,7 @@
 
 NO_OBJ=
 INCS=	_ctype.h _inttypes.h _langinfo.h _locale.h _monetary.h _stdio.h\
-	_stdlib.h _string.h _time.h _uchar.h _wchar.h
+	_stdlib.h _string.h _strings.h _time.h _uchar.h _wchar.h
 INCSDIR=${INCLUDEDIR}/xlocale
 
 .include <bsd.prog.mk>

include/xlocale/_string.h

@@ -53,9 +53,7 @@ size_t	 strxfrm_l(char *, const char *, size_t, locale_t);
 #ifdef _XLOCALE_H_
 #ifndef _XLOCALE_STRING2_H
 #define _XLOCALE_STRING2_H
-int	 strcasecmp_l(const char *, const char *, locale_t);
 char	*strcasestr_l(const char *, const char *, locale_t);
-int	 strncasecmp_l(const char *, const char *, size_t, locale_t);
 
 #endif /* _XLOCALE_STRING2_H */
 #endif /* _XLOCALE_H_ */

include/xlocale/_strings.h

@@ -0,0 +1,48 @@
+/*-
+ * Copyright (c) 2011, 2012 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#ifndef _LOCALE_T_DEFINED
+#define _LOCALE_T_DEFINED
+typedef struct	_xlocale *locale_t;
+#endif
+
+/*
+ * This file is included from both strings.h and xlocale.h.  We need to expose
+ * the declarations unconditionally if we are included from xlocale.h, but only
+ * if we are in POSIX2008 mode if included from string.h.
+ */
+
+#ifndef _XLOCALE_STRINGS1_H
+#define _XLOCALE_STRINGS1_H
+
+/*
+ * POSIX2008 functions
+ */
+int	 strcasecmp_l(const char *, const char *, locale_t);
+int	 strncasecmp_l(const char *, const char *, size_t, locale_t);
+#endif /* _XLOCALE_STRINGS1_H */

lib/libc/string/strcasecmp.3

@@ -30,7 +30,7 @@
 .\"     @(#)strcasecmp.3	8.1 (Berkeley) 6/9/93
 .\" $FreeBSD$
 .\"
-.Dd June 9, 1993
+.Dd May 29, 2014
 .Dt STRCASECMP 3
 .Os
 .Sh NAME
@@ -45,7 +45,7 @@
 .Fn strcasecmp "const char *s1" "const char *s2"
 .Ft int
 .Fn strncasecmp "const char *s1" "const char *s2" "size_t len"
-.In string.h
+.In strings.h
 .In xlocale.h
 .Ft int
 .Fn strcasecmp_l "const char *s1" "const char *s2" "locale_t loc"