Configure: Use standard --runstatedir option

Newer Autoconf defines --runstatedir option for setting directory for
run-time variable data. Use it instead our old --with-runtimedir.

configure.ac

@@ -53,9 +53,9 @@ AC_ARG_WITH([sysconfig],
 )
 
 AC_ARG_WITH([runtimedir],
-  [AS_HELP_STRING([--with-runtimedir=PATH], [path for runtime files @<:@LOCALSTATEDIR/run@:>@])],
-  [runtimedir="$with_runtimedir"],
-  [runtimedir="\$(localstatedir)/run"]
+  [AS_HELP_STRING([--with-runtimedir=PATH], [run-state data, obsolete variant of --runstatedir])],
+  [runstatedir="$with_runtimedir"],
+  []
 )
 
 AC_ARG_WITH([iproutedir],
@@ -91,7 +91,11 @@ esac
 AC_SUBST([objdir])
 AC_SUBST([exedir])
 AC_SUBST([srcdir_rel_mf])
-AC_SUBST([runtimedir])
+
+# Workaround for older Autoconfs that do not define runstatedir
+AS_IF([test -z "${runstatedir}"], [runstatedir='${localstatedir}/run'])
+AC_SUBST([runstatedir])
+
 
 if test "$enable_ipv6" = yes ; then
   ip=ipv6
@@ -112,7 +116,7 @@ if test "$enable_debug" = yes ; then
   CONTROL_SOCKET="bird$SUFFIX.ctl"
 else
   CONFIG_FILE="\$(sysconfdir)/bird$SUFFIX.conf"
-  CONTROL_SOCKET="$runtimedir/bird$SUFFIX.ctl"
+  CONTROL_SOCKET="\$(runstatedir)/bird.ctl"
 fi
 AC_SUBST([CONFIG_FILE])
 AC_SUBST([CONTROL_SOCKET])

tools/Makefile.in

@@ -71,7 +71,7 @@ tags:
 	cd $(srcdir) ; etags -lc `find $(static-dirs) $(addprefix $(objdir)/,$(dynamic-dirs)) $(client-dirs) -name *.[chY]`
 
 install: all
-	$(INSTALL) -d $(DESTDIR)/$(sbindir) $(DESTDIR)/$(sysconfdir) $(DESTDIR)/@runtimedir@
+	$(INSTALL) -d $(DESTDIR)/$(sbindir) $(DESTDIR)/$(sysconfdir) $(DESTDIR)/$(runstatedir)
 	$(INSTALL_PROGRAM) $(exedir)/bird $(DESTDIR)/$(sbindir)/bird@SUFFIX@
 	$(INSTALL_PROGRAM) $(exedir)/birdcl $(DESTDIR)/$(sbindir)/birdcl@SUFFIX@
 	if test -n "@CLIENT@" ; then								\

tools/Rules.in

@@ -39,6 +39,7 @@ bindir=@bindir@
 sbindir=@sbindir@
 sysconfdir=@sysconfdir@
 localstatedir=@localstatedir@
+runstatedir=@runstatedir@
 docdir=@prefix@/doc
 
 ifdef source