fix various issues

1. Make cluster.lck checking consistent and accurate.
2. Fix export_user actions to always put them in local_data.
3. Fix create_prefix.pl output file and input file searching. Basically
   this now looks for cty.dat and wpxloc.raw in local_data first and then
   falls backs to data. But puts the result in local_data unless the
   --system flag is set.