Juan 13/09/2016:Rules.LXgfortran.mk , compile the tools if gfortran >= 5.X

src/Rules.LXgfortran.mk

@@ -94,8 +94,10 @@ HDF_CONF= CFLAGS=-std=c99
 #
 # LIBTOOLS flags
 #
-#if MNH_TOOLS exists => compile the tools
+#if MNH_TOOLS exists => compile the tools if gfortran >= 5.X
+ifeq ($(shell test $$( gfortran -dumpversion | cut -b1 ) -ge 5 ; echo $$?),0)
 MNH_TOOLS = yes
+endif
 #
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