Support absolute paths in conf file names

CODES application conf files could refer to conf files in CODES. It would be best to be able to specify these as absolute paths. For example, in my APS config file, I have:

PARAMS
{
  ...
  net_config_file="/home/wozniak/proj/CODES/code/tests/conf/ng-mpi-tukey.dat";
}

Could configuration_get_value_relpath() skip prepending config_dir if the value has a leading slash?