Added Settlers.MapInterface.Action
which allows us to do a step by step actions for example
 first select building to build,
 second choose where to build,
 finaly send prepared request to server.

Example usage:
  var Actions = Settlers.MapInterface.ActionInstance;
  Actions.PrepareRequest('build', function(x){ console.log('Building '+x.building+', build at x = '+x.posX+', y = '+x.posY); });
  Actions.InitAction('build', {'building':'Farm'});
  Actions.FinalAction('build', {'posX':10, 'posY': 23});
  // Return to console: Building Farm, build at x = 10, y = 23