contrib/nfs: add configuration option to disable utils compilation

contrib/src/nfs/nfs-no-utils.patch

+diff -ru nfs/Makefile.am nfs-fixed/Makefile.am
+--- nfs/Makefile.am	2015-08-02 19:18:25.000000000 +0200
++++ nfs-fixed/Makefile.am	2016-01-14 14:33:06.000000000 +0100
+@@ -1,4 +1,4 @@
+-SUBDIRS = doc mount nfs nlm nsm portmap rquota lib include utils . $(MAYBE_EXAMPLES)
++SUBDIRS = doc mount nfs nlm nsm portmap rquota lib include $(MAYBE_UTILS) . $(MAYBE_EXAMPLES)
+ ACLOCAL_AMFLAGS = -I m4
+ 
+ pkgconfigdir = $(libdir)/pkgconfig
+diff -ru nfs/configure.ac nfs-fixed/configure.ac
+--- nfs/configure.ac	2015-08-02 19:18:25.000000000 +0200
++++ nfs-fixed/configure.ac	2016-01-14 14:43:43.000000000 +0100
+@@ -24,6 +24,14 @@
+ # We always want 64 bit file offsets
+ CFLAGS="${CFLAGS} -D_FILE_OFFSET_BITS=64"
+ 
++#option: utils
++AC_ARG_ENABLE([utils],
++              [AC_HELP_STRING([--enable-utils],
++                              [Build util programs])],
++	      [MAYBE_UTILS=""],
++	      [MAYBE_UTILS="utils"])
++AC_SUBST(MAYBE_UTILS)
++
+ #option: examples
+ AC_ARG_ENABLE([examples],
+               [AC_HELP_STRING([--enable-examples],

contrib/src/nfs/rules.mak

@@ -17,6 +17,8 @@ $(TARBALLS)/libnfs-$(NFS_VERSION).tar.gz:
 nfs: libnfs-$(NFS_VERSION).tar.gz .sum-nfs
 	$(UNPACK)
 	mv libnfs-libnfs-$(NFS_VERSION) libnfs-$(NFS_VERSION)
+	$(APPLY) $(SRC)/nfs/nfs-no-utils.patch
+	$(UPDATE_AUTOCONFIG)
 	$(MOVE)
 
 .nfs: nfs