Allow Silos to be created before the first Refinery is build

[rancid ocean]

This would be a great help on the bad spawn in Badlands, where you start without any resources nearby. We could build Silos first to reach the resources and then build our Refineries.

Besides the Badlands spawn this would also be helpful in other spawns where we can't place our refinery in the closest position to our resources, but if we can place a Silo first, we can get a more proper position.

[jaunty kindle]

giving just the original hq a slightly larger build radius could be a better alternative i think

[golden bear]

could be true