Automatic mod names for all but rotary, hack for sz_heat fire sfx.

sz_util/init.lua

@@ -3,7 +3,9 @@ dofile(minetest.get_modpath(minetest.get_current_modname())
 	.. "/sz_class.lua");
 
 -- Load subclasses defined in this mod.
-sz_class:loadsubclasses("sz_table")
+sz_class:loadsubclasses(
+	"sz_table"
+)
 sz_table:loadsubclasses(
 	"sz_pos",
 	"sz_facedir"

sz_util/sz_class.lua

@@ -8,7 +8,8 @@ function sz_class:new(init)
 end
 
 function sz_class:loadlibs(...)
-	local modpath = minetest.get_modpath(minetest.get_current_modname()) .. "/";
+	local modname = minetest.get_current_modname()
+	local modpath = minetest.get_modpath(modname) .. "/";
 	for i, class in ipairs({...}) do
 		dofile(modpath .. class .. ".lua")
 	end

sz_util/sz_pos.lua

@@ -240,7 +240,7 @@ end
 -- A safe accessor to get the groups for the node definition
 -- at this location that will always return a table.
 function sz_pos:groups()
-	return (self:nodedef() or { }).groups or { }
+	return sz_table:new((self:nodedef() or { }).groups or { })
 end
 
 -- Return true if this location contains only air.