Add direction parameter to statbars in HUD API
Fix health bar overlap when a larger texture is used
Class-ify caves & move to cavegen.cpp, fix cave regression, add caves to Mapgen V7
Fix hud_change stat argument retrieval
Fix findSpawnPos()
mgv7: Implement getGroundLevelAtPoint(), fix layer of topnodes at chunk Y boundaries, remove growGrass()
Merge 'upstream/master' into minemovie