Increase the health of Curved and Half-Diagonal Rails

[HeliGungir]

Currently, all rail shapes have the same base health: 200.
I suggest increasing the health of Curved and Half-Diagonal Rails to counterbalance their higher material cost and larger surface area.

• Straight rails cost 1 Rail item and cover 4 tiles
• Diagonal rails cost 1 Rail item and cover ~8 tiles (They're actually still called Straight Rails in the tooltip)
• Half-Diag rails cost 2 Rail items and cover ~12 tiles
• Curved rails cost 3 Rail items and cover ~12 tiles

I think 200 health for Straight and Diagonal Rails, 300 for Half-Diagonal Rail, and 400 for Curved Rails would work well. These numbers are a compromise between scaling their health by item cost vs. scaling their health by surface area.

[boskid]

I see no reason to apply this. Those rails are longer so they need more material but they break with the same damage.

[HeliGungir]

Essentially: Curves are more fragile than straights. They cost more to build and have a larger surface area, yet they don't have more health.

When biters attack railroad tracks, they'll destroy 10 Curved Rails much more quickly than 30 Straight Rails, despite both requiring the same number of Rail items, and despite both covering a similar distance and similar surface area.