[dunecontrol] evaluate CMAKE_MODULE_PATH from opts file

up to now a CMAKE_MODULE_PATH environment variable was properly considered
and appended to the cmake parameters. This did not work for an environment
variable specified in the opts file. This patch makes the behaviour
consistent between shell environment and opts file variables.

(fixes #25)

bin/dunecontrol

@@ -221,6 +221,7 @@ load_opts() {
   if test "x$DUNE_OPTS_FILE" != "x"; then
     if test "$command" = "configure"; then
       CMAKE_FLAGS="$(. $DUNE_OPTS_FILE; eval echo \$CMAKE_FLAGS)"
+      CMAKE_MODULE_PATH="$(. $DUNE_OPTS_FILE; eval echo \$CMAKE_MODULE_PATH)"
     fi
     CMD_FLAGS_FROM_FILE="$(eval ${COMMAND}_FLAGS=""; . $DUNE_OPTS_FILE; eval echo \$${COMMAND}_FLAGS)"
   fi