Fracking: Add more layers of rock; tweak layer algorithm

Other rock types do not affect the model, just the color
of the layers.

Tweak layout so that sinewave frequency is lower and layers
can be angled and cut into each other.

[#54231794]
Fracking: Make it possible to show earth patches from start

[#53251043]
Fracking: Create variant that shows layers from start

[#53251043]
Fracking: Create shale gas, trapped in shale layer

Gas jiggles slowly around shale. Does not affect the model.
Shale gas dies when it touches open space, so as wells are
added shale gas will slowly decrease.

Gas is invisible if patches are hidden.

[#54232158]
Fracking: Model starts off playing

[#54232158]