CONFIG: update MPICH and MVAPICH versions/rules

- Note: mpich now builds libmpi.so instead of libmpich.so

- define both -DMPICH_SKIP_MPICXX and -DOMPI_SKIP_MPICXX regardless of
  using openmpi or mpich. This simplifies the files and does not harm.

etc/config.sh/mpi

@@ -145,7 +145,7 @@ SYSTEMMPI)
     ;;
 
 MPICH)
-    export FOAM_MPI=mpich-3.2
+    export FOAM_MPI=mpich-3.3
     export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$FOAM_MPI
     export MPI_HOME=$MPI_ARCH_PATH
 
@@ -169,6 +169,19 @@ MPICH-GM)
     _foamAddLib     $GM_LIB_PATH
     ;;
 
+MVA2MPI)  # MVAMPICH2
+    export FOAM_MPI=mvapich2-2.3
+    export MPI_ARCH_PATH=$WM_THIRD_PARTY_DIR/platforms/$WM_ARCH$WM_COMPILER/$FOAM_MPI
+
+    # Could be sourced from ThirdParty with incomplete environment
+    if command -v _foamAddLibAuto > /dev/null 2>&1  # Normal sourcing
+    then
+        _foamAddPath    $MPI_ARCH_PATH/bin
+        _foamAddMan     $MPI_ARCH_PATH/share/man
+        _foamAddLibAuto $MPI_ARCH_PATH  lib$WM_COMPILER_LIB_ARCH
+    fi
+    ;;
+
 CRAY-MPICH)
     export FOAM_MPI=cray-mpich
     export MPI_ARCH_PATH=$MPICH_DIR