[2.0.6] absurd roboport construction ranges slow the game to a crawl

[Quezler]

if you want a roboport to cover the entire world you could do something silly like this in 1.1 with no repercussions (or so i recall)

data.raw["roboport"]["roboport"].construction_radius = 100000
(actually, this is just 100k, since the lag spike for 1 million (what you need for full coverage) is so great i got bored of waiting for the world to even load)

however in the current version:
- loading a world takes several seconds, with it hanging on "entity setup" for like all of that
- breaking the single roboport takes several seconds
- placing a roboport takes several seconds
- the game hangs around 10 ups/fps when you've managed to place one

[Quezler]

upon closer rubber ducking (https://discord.com/channels/1214952937 ... 1548608543) it appears radar_range is to blame, i had not noticed it had grown alongside the construction area (fff mentioned roboports had 2 radar range, but apparently it is derived), the game just *does not* like to have a roboport with an effective radar range of 3125, it caught me off guard that this property had a mind of its own, consider this closed/solved, but some change in defaults/documentation might be wise.