NEW: getRoboter()->sendMessage(...) encapsulates the UDP sending and
suppresses it in test mode

NEW: robos switch roles (goal keeper <> striker) if goal keeper is
nearer to the ball (e.g. goal keeper defends its goal, ball stays near
to the goal, striker would have problems to navigate to the ball
avoiding the ball, the goal keeper, and the goal -> solution: goal
keeper becomes striker and shoots the ball towards enemy goal while
striker becomes goal keeper and directly drives to its own goal center)

IMPROVED: getRoboter()->shoot() uses the speed constant from Constants.h

IMPROVED: Striker.state_moveToBall renamed to
Striker.state_moveToShooting pos as this is what it does ;)

IMPROVED: striker does not block the thread while waiting for the goal
keeper to turn to the ball (implemented new state)

IMPROVED: runStriker and runGoalKeeper states renamed to
state_runStriker and state_runGoalKeeper