Go to application directory for pbsdsh batch mode

Go to the application directory before invoking PBS distributed shell
(pbsdsh) parallel runs, so that they can be launched from any location,
in particular from the home directory when submitting jobs remotely via
ssh.

HEN_HOUSE/scripts/run_user_code_batch

@@ -399,6 +399,7 @@ if test $egs_batch_system = "pbsdsh"; then
  fi
 
  # submit the following stdin script to qsub, which will invoke the run_pbsdsh_task script
+ cd $egs_home/$user_code
  $batch_command $batch_options $queue $other_args <<EOF
 #!/bin/sh
 #PBS -l procs=$n_parallel