BLOCK-EXIT      "makes a mobile block an exit under certain conditions"


  dirs          one or more directions, which should be blocked by the
                relating mob (space is seperator)

  flags         optional flags: (seperated by spaces)

                        sameside        blocks chars of same side
                        otherside       blocks chars of other side
                        nomob           do not trigger on mobiles

  room          only trigger in the given room (optional)

  minalign      minimum align (optional)
  maxalign      maximum align (optional)

  seeinvis      if set with anyvalue, the mobile will also trigger on chars,
                which it cannot see

  tochar        if char was blocked: echo to the character
  toroom        if char was blocked: echo to the room

  okchar        if char passed: echo to char
  okroom        if char passed: echo to room