salt.modules.freebsdjail: make this module a bit more resilient
salt.modules.freebsdjail: make this module a bit more resilient

    - Use with statement for some opens to not have issues wtih
      dangling file handles kept open by the python interpreter
    - Switch checks from os.path.isfile() and then blindly opening
      to os.access(fname, os.R_OK), which will return False nicely
      if permission is denied *or* the file doesn't exist, preventing
      unlikely yet potential unhandled tracebacks

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt