Smart Device detector

[Yoric]

Meta-bug: #2.

In this Highschool, when a wifi/broadband-enabled device enters or
is turned on in the exam perimeter, send a message to the desktop
server. Give as much detail as possible on where the device is, so
that the teachers can come and frown at offending student.

Can be expressed as

I need:
- a `wifi detector` (zero or more) with property `activity detected`;
- a `broadband detector` (zero or more) with property `activity
detected`;
- a `communication channel to an application` with capability `send data``?

1. When `activity detected` of `wifi detector` switches to true
  do `send data` to `communication channel to an application`:
    `sensor details` of `activity detected`

This application is meant to be attached to a specific front-end.

Input devices

• a wifi detector with property activity detected;
• a broadband detector with property activity detected.

Output devices

• a communication channel to an application with capability send data;

FIXME: I'm not entirely sure about that one. This detector is meant to
be used with a specific front-end. What's the best way to specify
front-end? Do we want to be so generic that we can change front-end?
That sounds over-engineered, but I can't think of anything simpler atm.