Allow spawning particles from the server, from lua

Spawn single particles or make use of ParticleSpawner for many randomly spawned particles.
Accessible in Lua using minetest.spawn_particle and minetest.add_particlespawner.
Increase Protocol Version to 17.

Conflicts:
	src/clientserver.h

src/clientserver.h

@@ -82,6 +82,9 @@ SharedBuffer<u8> makePacket_TOCLIENT_TIME_OF_DAY(u16 time, float time_speed);
 	PROTOCOL_VERSION 17:
 		Serialization format change: include backface_culling flag in TileDef
 		Added rightclickable field in nodedef
+		TOCLIENT_SPAWN_PARTICLE
+		TOCLIENT_ADD_PARTICLESPAWNER
+		TOCLIENT_DELETE_PARTICLESPAWNER
 */
 
 #define LATEST_PROTOCOL_VERSION 17
@@ -359,6 +362,7 @@ enum ToClientCommand
 		u8[len] name
 		[2] serialized inventory
 	*/
+
 	TOCLIENT_SHOW_FORMSPEC = 0x44,
 	/*
 		[0] u16 command
@@ -384,6 +388,46 @@ enum ToClientCommand
 		f1000 movement_liquid_sink
 		f1000 movement_gravity
 	*/
+
+	TOCLIENT_SPAWN_PARTICLE = 0x46,
+	/*
+		u16 command
+		v3f1000 pos
+		v3f1000 velocity
+		v3f1000 acceleration
+		f1000 expirationtime
+		f1000 size
+		u8 bool collisiondetection
+		u32 len
+		u8[len] texture
+	*/
+
+	TOCLIENT_ADD_PARTICLESPAWNER = 0x47,
+	/*
+		u16 command
+		u16 amount
+		f1000 spawntime
+		v3f1000 minpos
+		v3f1000 maxpos
+		v3f1000 minvel
+		v3f1000 maxvel
+		v3f1000 minacc
+		v3f1000 maxacc
+		f1000 minexptime
+		f1000 maxexptime
+		f1000 minsize
+		f1000 maxsize
+		u8 bool collisiondetection
+		u32 len
+		u8[len] texture
+		u32 id
+	*/
+
+	TOCLIENT_DELETE_PARTICLESPAWNER = 0x48,
+	/*
+		u16 command
+		u32 id
+	*/
 };
 
 enum ToServerCommand