Mgv5: Remove blobgen. Remove crumble and wetness noises

Add large pseudorandom caves below -256
De-link terrain level from water_level
Cavegen: Mgv5 large cave code

src/cavegen.h

@@ -22,9 +22,55 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #define VMANIP_FLAG_CAVE VOXELFLAG_CHECKED1
 
+class MapgenV5;
 class MapgenV6;
 class MapgenV7;
 
+class CaveV5 {
+public:
+	MapgenV5 *mg;
+	MMVManip *vm;
+	INodeDefManager *ndef;
+
+	NoiseParams *np_caveliquids;
+
+	s16 min_tunnel_diameter;
+	s16 max_tunnel_diameter;
+	u16 tunnel_routepoints;
+	int dswitchint;
+	int part_max_length_rs;
+
+	bool large_cave_is_flat;
+	bool flooded;
+
+	s16 max_stone_y;
+	v3s16 node_min;
+	v3s16 node_max;
+
+	v3f orp;  // starting point, relative to caved space
+	v3s16 of; // absolute coordinates of caved space
+	v3s16 ar; // allowed route area
+	s16 rs;   // tunnel radius size
+	v3f main_direction;
+
+	s16 route_y_min;
+	s16 route_y_max;
+
+	PseudoRandom *ps;
+
+	content_t c_water_source;
+	content_t c_lava_source;
+	content_t c_ice;
+
+	int water_level;
+
+	CaveV5() {}
+	CaveV5(MapgenV5 *mg, PseudoRandom *ps);
+	void makeCave(v3s16 nmin, v3s16 nmax, int max_stone_height);
+	void makeTunnel(bool dirswitch);
+	void carveRoute(v3f vec, float f, bool randomize_xz, bool is_ravine);
+};
+
 class CaveV6 {
 public:
 	MapgenV6 *mg;