ENH: introduce a separate makeOPENMPI

- makes is easier to quickly build different versions and reduces
  clutter in Allwmake.

- provide some quick '-test' options for makeCGAL, makeFFTW etc
  to reduce duplication of logic in Allwmake.

makeFFTW

@@ -31,6 +31,21 @@
 # ----------------------------------------------
 # NO USER-CONFIGURABLE SETTINGS WITHIN THIS FILE
 #------------------------------------------------------------------------------
+# Short-circuit test for an installation
+if [ "$1" = "-test" ]
+then
+    [ "$#" -eq 2 ] || { echo "${0##*/} -test : needs 1 argument"; exit 1; }
+    dir="$2" # <- FFTW_ARCH_PATH
+    if [ -d "$dir/include" -a -r "$dir/lib$WM_COMPILER_LIB_ARCH/libfftw3.so" ]
+    then
+        echo "    FFTW headers in $dir/include"
+        echo "    FFTW libs    in $dir/lib$WM_COMPILER_LIB_ARCH"
+        exit 0
+    else
+        exit 2
+    fi
+fi
+#------------------------------------------------------------------------------
 # Run from third-party directory only
 cd ${0%/*} && wmakeCheckPwd -q "$WM_THIRD_PARTY_DIR" 2>/dev/null || {
     echo "Error (${0##*/}) : not located in \$WM_THIRD_PARTY_DIR"