Added popular maps and auto-create pickup

Changed the default maps to those most played by the community. Reasoning is that there is going to be pushback from the community if gravelpit etc is randomly selected, so keep it to the same 5 boring maps but leave the option to change to something more exciting. 

Changed it so that a new pickup is automatically created when the current one is full. This is a requested feature from the community and will hopefully keep messages to admins down. 

TODO: With regards to the random maps, it should be made so that the same map should not be chosen twice.