During insall, make sure that /usr/bin/perl exists and create it if not.

As of June 2015, the FreeBSD port no longer maintains the /usr/bin/perl
symlink which we rely on, so it may be wrong or missing.

clientside/tmcc/freebsd10/GNUmakefile.in

 #
-# Copyright (c) 2000-2013 University of Utah and the Flux Group.
+# Copyright (c) 2000-2015 University of Utah and the Flux Group.
 # 
 # {{{EMULAB-LICENSE
 # 
@@ -22,7 +22,7 @@
 #
 
 #
-# XXX ONLY RUN THIS INSTALL ON A FREEBSD 6 TESTBED NODE!
+# XXX ONLY RUN THIS INSTALL ON A FREEBSD 10.x TESTBED NODE!
 #
 # Trivial. These things just need to be installed into the right place
 # on a testbed node before cutting an image.
@@ -73,11 +73,19 @@ subboss-install:	bincheck basefbsd-subboss-install etc-install \
 
 simple-install:	script-install bin-install
 
+#
+# XXX make sure the isc-dhcpd port is installed,
+# XXX as of June 2015, the FreeBSD port no longer maintains the
+#     /usr/bin/perl symlink which we rely on, so it may be wrong or missing.
+#
 bincheck:
 	@if [ ! -x /usr/local/sbin/dhclient ]; then \
 		echo "Need to install net/isc-dhcp3-client port"; \
 		false; \
 	fi
+	@if [ ! -x /usr/bin/perl ]; then \
+		ln -sf /usr/local/bin/perl5 /usr/bin/perl; \
+	fi
 
 dir-install:
 	$(INSTALL) -m 755 -o root -g wheel -d $(DESTDIR)/boot