Ore: Add Vein ore type
Biome API: Add shore top and shore filler nodes, underwater node, water top node. Add water top depth and shore height parameters. Remove water dust node
Cavegen: Fix copy & paste error (solves #2020)
Decoration: Add height_min and height_max parameters

Also set default height_min/height_max to -31000 and 31000,
respectively, for ore and biomes
Skip further loading of client if there was an exit signal
MainMenu: Save 'hide gamemods' and 'hide modpack contents' checkbox state (fixes #1960)
Faster string.split implementation.
Fix MSVC compiler warning about passing this pointer in initializer list
LuaItemStack: Fix and document behavior of set_name, set_count, set_wear, set_metadata