Lava Tweaks

This mod changes lava in a few ways.

* First, standing near lava for more than about 5 seconds will set the player on fire.

* Second, lava with air above it outside of the nether will solidify into basalt (can still be flash cooled with a water bucket)

* Third, lava in contact with stone, earth etc will also turn those blocks into basalt.

* Fourth, cobblestone generators now make basalt cobblestone and basalt.

* Fifth, staying in the nether for more than 5 minutes will set the player on fire, the time limit can be measured via the effect "Sweltering."