Make the walking speed modifiers generic

[felixbade]

The mod could iterate through all tiles in data.json and set their new speed according to their previous speed instead of their tile name. This way the mod would be compatible with all mods that introduce new tiles, and it would be easier to make the speed changes consistent. This feature might be able to reduce the total amount of code as well.

The downside of course would be that if there is some other mod that changes the walking speeds, the two mods together would modify the speeds twice. That’s probably not a big deal though.

[felixbade]

In the simplest possible implementation this doesn’t calculate the new speeds with any fancy formula, but simply looks for specific values and replaces them with specific other values (e.g. 1.3 → 1.8).

It just has to make sure the loop doesn’t modify the same values twice (e.g. if 1.8 → 3.0 then 1.3 shouldn’t become 3.0).