separate mpi-dependent build files

src/Pstream/Allwmake

@@ -5,18 +5,18 @@ set -x
 wmake libso dummy
 
 case "$WM_MPLIB" in
-GAMMA)
-    wmake libso gamma
-    ;;
-
 LAM | *MPI* )
-    WM_OPTIONS=${WM_OPTIONS}$WM_MPLIB
     set +x
     echo
     echo "Note: ignore spurious warnings about missing mpicxx.h headers"
     set -x
-    wmake libso mpi
+    (WM_OPTIONS=${WM_OPTIONS}$WM_MPLIB; wmake libso mpi)
     ;;
+
+#GAMMA)
+#    wmake libso gamma
+#    ;;
 esac
 
+
 # ----------------------------------------------------------------- end-of-file

src/decompositionAgglomeration/Allwmake

@@ -6,7 +6,7 @@ wmake libso decompositionMethods
 
 if [ -d "$FOAM_MPI_LIBBIN" ]
 then
-    wmake libso parMetisDecomp
+    (WM_OPTIONS=${WM_OPTIONS}$WM_MPLIB; wmake libso parMetisDecomp)
 fi
 
 wmake libso MGridGenGamgAgglomeration