Catch more fork() errors.
  Moved sleep_until_file_created() here from "mysql-test-run.pl".
  Improved debug output.
mtr_io.pl:
  Improved mtr_get_opts_from_file(), try to mimic some sh.
mysql-test-run.pl:
  Cleaned up the timeout handling.
  Created new function environment_setup().
  Corrected time zone handling.
  Moved sleep_until_file_created() to "lib/mtr_process.pl".
  Improved debug output.