Install expected kyua docs.

The "kyua about" command assumes these files exist causing tests
supplied devel/kyua to fail.

Fix a bug defining the default KYUA_DOCDIR so the installed files can be
found.

Reported by:	jenkins tests
Reviewed by:	lwhsu
Sponsored by:	DARPA
Differential Revision:	https://reviews.freebsd.org/D24187

etc/mtree/BSD.usr.dist

@@ -219,6 +219,8 @@
             ..
             atf
             ..
+            kyua
+            ..
             legal
             ..
             llvm

lib/kyua/Makefile.kyua

@@ -3,7 +3,7 @@
 KYUA_VERSION=	0.13
 
 KYUA_CONFDIR=	/etc/kyua
-KYUA_DOCDIR=	/nonexistant
+KYUA_DOCDIR=	/usr/share/doc/kyua
 KYUA_EGDIR=	/usr/share/examples/kyua
 KYUA_MISCDIR=	/usr/share/kyua/misc
 KYUA_STOREDIR=	/usr/share/kyua/store

lib/kyua/cli/Makefile

@@ -4,7 +4,7 @@ KYUA_LIB=	cli
 INTERNALLIB=
 LIBADD=		kyua_drivers kyua_engine kyua_model kyua_store kyua_utils
 CFLAGS+=	-DKYUA_CONFDIR=\"${KYUA_CONFDIR}\"		\
-		-DKYUA_DOCDIR=\"${KYUA_CONFDIR}\"		\
+		-DKYUA_DOCDIR=\"${KYUA_DOCDIR}\"		\
 		-DKYUA_MISCDIR=\"${KYUA_MISCDIR}\"		\
 		-DPACKAGE=\"kyua\"				\
 		-DPACKAGE_NAME=\"Kyua\"				\

usr.bin/kyua/Makefile

@@ -28,11 +28,14 @@ CFLAGS+=	-I${KYUA_SRCDIR}
 # kyua uses auto_ptr
 CFLAGS+=	-Wno-deprecated-declarations
 
-FILESGROUPS=	EXAMPLES MISC STORE
+FILESGROUPS=	DOCS EXAMPLES MISC STORE
 
 CONFS=		kyua.conf
 CONFSDIR=	${KYUA_CONFDIR}
 
+DOCS=		AUTHORS CONTRIBUTORS LICENSE
+DOCSDIR=	${KYUA_DOCDIR}
+
 EXAMPLES=	Kyuafile.top kyua.conf
 EXAMPLESDIR=	${KYUA_EGDIR}
 .PATH:		${KYUA_SRCDIR}/examples