make external connection readable

external connections should:

• have a name
  • the name must be unique for the Board
• have a description
  • this description needs to descripe what can be recieved from the connection and what needs to be sent to it
• a list of small state descriptions
  • when the program uses the connection the conection notifies the debugger about the new state
    • this happens even in non debug mode to allow fast abort/finish if an invalid/finish state is reached
  • invalid states can have a guess about the valid state that was (probably) tried to reach
  • states types:
    • normal: not yet invalid, but the program still needs to do stuff with this connection to finish
    • finish: the program does not need to do anything with this connection before it terminates
    • invalid: it is impossible for the program to reach the finish state
      • states of this type may not be reported in the list of known states
      • these states should usually get dynamically generated when reached

the list of known states should also be visible on a second overlay.