Add custom air support request as a parallel feature like suppression and dismount

[Chromium18]

Add an additional submodule that could be true/false that basically does this:

Create a message system that interacts with the clients by creating custom tasks for ground units' air support requests (CAS/BAI), whithout getting into details on procedure. It should basically only be a "tasking list". Each task should be added for a limited timeframe and available in F10 menù, and the task addition will be announced by a trigger message to the coalition).

The F10 menù layout will be divided in available tasks and acknowledge task. Available task name should only be the mission type and the reference geographic grid and lat/lon, to be easily placeable over the map (or, else, a task ID and a mark added to the map.. but I don't like that so much).

Once an available task is choosen, the task details should be shown, like situation allied composition, known enemy and coordinates of both.

In the acknowledge task a client should choose the task, if done, task disappear by available task. No further detail should be added in this moment (maybe an assigned task menù later).