fix warnings for 2.0

[ahicks92]

There are some variables in control.lua set up in on_configuration_changed that I had to set to empty to get things to launch. They tell warnings about certain kinds of buildings. Now that prototypes is a separate variable it might be possible to just compute these in the warning menu as top-level constants, but in any case they need to be restored. In practice they are figuring out which prototypes to categorize as various things by checking for attributes, but just listing out the prototype types and what category they go in is probably significantly better than that in any case.