added distributed-memory parallelism using MPI, overhaul of error and message routines.

Former-commit-id: f79191bff5f13f70fb514cd4959cb6699d917658

configure.in

@@ -17,7 +17,7 @@
 
 # init the project
 AC_INIT(src/space.c)
-VERSION="0.0.1"
+VERSION="0.1.0"
 AC_SUBST(VERSION)
 AM_INIT_AUTOMAKE(SWIFT,VERSION)
 AC_GNU_SOURCE
@@ -57,6 +57,18 @@ ACX_PTHREAD([LIBS="$PTHREAD_LIBS $LIBS" CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
     or use CPPFLAGS and LDFLAGS if the library is installed in a
     non-standard location.]))
     
+    
+# Check for MPI
+AC_ARG_ENABLE([mpi],
+    [AS_HELP_STRING([--enable-mpi],[compile with functionality for distributed-memory parallelim using MPI @<:@default=yes@:>@])],
+    [if test "x$enable_mpi" != "xno"
+     then
+        ACX_MPI([ CC="$MPICC" AC_DEFINE(HAVE_MPI,1,[Define if you have the MPI library.]) ])
+     fi],
+    [ACX_MPI([ CC="$MPICC" AC_DEFINE(HAVE_MPI,1,[Define if you have the MPI library.]) ])])
+AM_CONDITIONAL([HAVEMPI],[test -n "$MPICC"])
+
+    
 # check for zlib
 AC_CHECK_LIB(z,gzopen,[
     AC_DEFINE([HAVE_LIBZ],[1],[Set to 1 if zlib is installed.])