Update biomes enum for MC 1.8

[deathcap]

MC 1.8 update for lib/enums/biomes.json (probably the simplest of the enums). Based on burger.json from https://github.com/deathcap/Burger/tree/mc18 through bin/generate_enums.java, with the following caveats:

• Removed biome.height - does anyone know what this was for? (http://minecraft.gamepedia.com/Biome has no mention of a height property, the old pre-1.8 Burger had it but is not clear where in 1.8 the height comes from, if anywhere). In any case, nothing else seems to reference this value, I suspect it is fairly safe to remove.
• Some of the temperatures and rainfall values were not specified in the constructors for some reason (couldn't get Burger to extract), so I used http://minecraft.gamepedia.com/Biome and https://github.com/erich666/Mineways/blob/master/Win/biomes.cpp to fill in the gaps
• "Modified" biomes (128 + original ID) are not included, these appear to be handled differently (highly dynamic, may need to be analyzed manually, or dumped at runtime)
• Other enums not yet updated, will require more work to identify the structure for extraction (so far: https://gist.github.com/deathcap/6efd375e010a005040f8)

[roblabla]

Is this ready to merge ? It looks good. Concerning "modified biomes", I think whenever we get a biome from the server, doing a simple if (biome > 128) biome -= 128 might work. From what I read on the gamepedia, only the name changes.

[deathcap]

👍 ok to merge (imho the modified biomes should be handled separately, since they inherit the same properties from this enum)