Move scriptapi to separate folder (by sapier)

On the lua side, notably minetest.env:<function>(<args>) should now
be replaced by minetest.<function>(<args>).
The old way is and will stay supported for a long time.

Also:
Update and clean up lua_api.txt (by celeron55)
Move EnvRef to lua and remove add_rat and add_firefly (by kahrl)
Add separate src/util/CMakeLists.txt, other minor fixes (by kahrl)

src/script/lua_api/l_particles.cpp

@@ -0,0 +1,149 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "cpp_api/scriptapi.h"
+#include "common/c_converter.h"
+#include "lua_api/l_base.h"
+#include "lua_api/l_particles.h"
+#include "server.h"
+#include "common/c_internal.h"
+
+bool ModApiParticles::Initialize(lua_State *L, int top) {
+	bool retval = true;
+
+	retval &= API_FCT(add_particle);
+	retval &= API_FCT(add_particlespawner);
+	retval &= API_FCT(delete_particlespawner);
+
+	return retval;
+}
+
+// add_particle(pos, velocity, acceleration, expirationtime,
+// 		size, collisiondetection, texture, player)
+// pos/velocity/acceleration = {x=num, y=num, z=num}
+// expirationtime = num (seconds)
+// size = num
+// texture = e.g."default_wood.png"
+int ModApiParticles::l_add_particle(lua_State *L)
+{
+	// Get parameters
+	v3f pos = check_v3f(L, 1);
+	v3f vel = check_v3f(L, 2);
+	v3f acc = check_v3f(L, 3);
+	float expirationtime = luaL_checknumber(L, 4);
+	float size = luaL_checknumber(L, 5);
+	bool collisiondetection = lua_toboolean(L, 6);
+	std::string texture = luaL_checkstring(L, 7);
+
+	if (lua_gettop(L) == 8) // only spawn for a single player
+	{
+		const char *playername = luaL_checkstring(L, 8);
+		getServer(L)->spawnParticle(playername,
+			pos, vel, acc, expirationtime,
+			size, collisiondetection, texture);
+	}
+	else // spawn for all players
+	{
+		getServer(L)->spawnParticleAll(pos, vel, acc,
+			expirationtime, size, collisiondetection, texture);
+	}
+	return 1;
+}
+
+// add_particlespawner(amount, time,
+//				minpos, maxpos,
+//				minvel, maxvel,
+//				minacc, maxacc,
+//				minexptime, maxexptime,
+//				minsize, maxsize,
+//				collisiondetection,
+//				texture,
+//				player)
+// minpos/maxpos/minvel/maxvel/minacc/maxacc = {x=num, y=num, z=num}
+// minexptime/maxexptime = num (seconds)
+// minsize/maxsize = num
+// collisiondetection = bool
+// texture = e.g."default_wood.png"
+int ModApiParticles::l_add_particlespawner(lua_State *L)
+{
+	// Get parameters
+	u16 amount = luaL_checknumber(L, 1);
+	float time = luaL_checknumber(L, 2);
+	v3f minpos = check_v3f(L, 3);
+	v3f maxpos = check_v3f(L, 4);
+	v3f minvel = check_v3f(L, 5);
+	v3f maxvel = check_v3f(L, 6);
+	v3f minacc = check_v3f(L, 7);
+	v3f maxacc = check_v3f(L, 8);
+	float minexptime = luaL_checknumber(L, 9);
+	float maxexptime = luaL_checknumber(L, 10);
+	float minsize = luaL_checknumber(L, 11);
+	float maxsize = luaL_checknumber(L, 12);
+	bool collisiondetection = lua_toboolean(L, 13);
+	std::string texture = luaL_checkstring(L, 14);
+
+	if (lua_gettop(L) == 15) // only spawn for a single player
+	{
+		const char *playername = luaL_checkstring(L, 15);
+		u32 id = getServer(L)->addParticleSpawner(playername,
+							amount, time,
+							minpos, maxpos,
+							minvel, maxvel,
+							minacc, maxacc,
+							minexptime, maxexptime,
+							minsize, maxsize,
+							collisiondetection,
+							texture);
+		lua_pushnumber(L, id);
+	}
+	else // spawn for all players
+	{
+		u32 id = getServer(L)->addParticleSpawnerAll(	amount, time,
+							minpos, maxpos,
+							minvel, maxvel,
+							minacc, maxacc,
+							minexptime, maxexptime,
+							minsize, maxsize,
+							collisiondetection,
+							texture);
+		lua_pushnumber(L, id);
+	}
+	return 1;
+}
+
+// delete_particlespawner(id, player)
+// player (string) is optional
+int ModApiParticles::l_delete_particlespawner(lua_State *L)
+{
+	// Get parameters
+	u32 id = luaL_checknumber(L, 1);
+
+	if (lua_gettop(L) == 2) // only delete for one player
+	{
+		const char *playername = luaL_checkstring(L, 2);
+		getServer(L)->deleteParticleSpawner(playername, id);
+	}
+	else // delete for all players
+	{
+		getServer(L)->deleteParticleSpawnerAll(id);
+	}
+	return 1;
+}
+
+ModApiParticles modapiparticles_prototyp;