Negative amount of beacon modules

[ingmarins]

It is possible to specify negative amount of modules for beacons. This results in negative amount of factories required, and with speed modules this can result in total power of f.e. -1234 W (without k).

[adrianvanderwal]

Confirmed bug.

[baryluk]

Is this pushed? It still goes negative when you use the number spinner. Also it is probably also wise to cap it to some max (16?). Globally or depending on type of structure (i.e. less for assemblers, more for big things like silo, etc).