Trains a unit of type id (rawcode) at town with index 'town', the integer 'qty' will work if the player has 'qty' building that can train this unit however this action will not queue, example, the player has 1 barracks and qty= 3 then 1 unit will be trained. Lets suppose that another barracks is built then 2 units will be trained. Will return true if the unit can be trained successfully, i.e. the AI player has all the resources and requirments of the training as well as the building that will start the training