Building proximities features

[khooobs]

Extend the concept of building proximities/co-operation (inspired by PW)

i.e:

Steel Industry

• Ore Depot - Reduce cycle time when built near coal and/or iron mine (productivity reduction mean less consumption)

Industrial Substation

• A power station designed specifically for industrial sites. It will provide a customised electricity bonus (an alternative to using standard electricity due to Industries can work with electricity and without depots #44, and will be used to Assembly Line #32)