Attempts to revert 'smart' belt building behaviour to 1.1 off state, specifically disabling the auto-building of undergrounds when building past an obstacle. Can also enable the building over of belts and undergrounds oriented in different directions.

Demo vid: youtube

Cannot change the "build in a line" logic, since that isn't exposed to the modding interface. But personally, I was more annoyed by the random undergrounds appearing.

Issues:
- Underground replacement works by detecting when (pairs of) undergrounds are built, while the player is holding transport-belt, and replacing them with belt. However, this means that if the player has no underground belts in their inventory, there will be a 'Missing underground belts' alert, and the regular belts will also fail to be placed.
- Due to it being a script replacing undergrounds/belts, it does not play that well with the undo function. Some actions can be undone, but others are buggy. Ghostly undergrounds sometimes appear when undoing.
- Works properly in Factorio 2.0.11. Currently, Factorio 2.0.12 (and 13) have issues with smart belt placing in the base game (forum link).