Enable MPI support from DUNE with --enable-parallel

configure

@@ -22,6 +22,7 @@ Optional Features:
   --disable-silent-rules  print every compilation statement as executed
   --enable-system-debug   put .debug files in global GDB debug dir
                           [default=yes if prefix=/usr, no otherwise]
+  --enable-parallel       process in parallel using MPI [default=no]
   --enable-openmp         activate experimental support for OpenMP
   --disable-option-checking  ignore unrecognized --enable/--with options
 
@@ -93,6 +94,7 @@ buildtype=Debug
 pch_use=
 #use_openmp=" -DUSE_OPENMP=OFF"
 use_openmp=
+use_mpi=
 #silent_rules=" -DCMAKE_VERBOSE_MAKEFILE=OFF"
 silent_rules=
 #debug_loc=" -DSYSTEM_DEBUG=OFF"
@@ -226,6 +228,10 @@ for OPT in "$@"; do
               use_openmp=" -DUSE_OPENMP=OFF"
               pkgname=""
               ;;
+            parallel)
+              use_mpi=" -DUSE_MPI=OFF"
+              pkgname=""
+              ;;
             agmg |\
             ert  |\
             superlu)
@@ -260,6 +266,11 @@ for OPT in "$@"; do
               # special flag; don't set shared/static
               shared=""
               ;;
+            parallel)
+              use_openmp=" -DUSE_MPI=ON"
+              # special flag; don't set shared/static
+              shared=""
+              ;;
             # this flag is just for compatibility with the deprecation
             # flag in DUNE, so we can build without warnings
             fieldvector-size-is-method)
@@ -308,7 +319,7 @@ for a in "${VARS[@]}"; do
 done
 
 # pass everything on to CMake
-CMDLINE="env ${ENVVARS} ${CMAKE_COMMAND} \"${srcdir}\" \"-DCMAKE_INSTALL_PREFIX=$prefix\" -DCMAKE_BUILD_TYPE=${buildtype}${pch_use}${silent_rules}${debug_loc}${use_openmp} ${FEATURES}"
+CMDLINE="env ${ENVVARS} ${CMAKE_COMMAND} \"${srcdir}\" \"-DCMAKE_INSTALL_PREFIX=$prefix\" -DCMAKE_BUILD_TYPE=${buildtype}${pch_use}${silent_rules}${debug_loc}${use_openmp}${use_mpi} ${FEATURES}"
 echo --- calling CMake ---
 echo ${CMDLINE}
 eval exec ${CMDLINE}