Better technic support

The hitech weapons are only compatible with the stable version of
Technic Plus. This change adds support for Technic and Technic Plus
Beta.

It also updates the code to use the new metadata functions instead
of the deprecated get_metadata and set_metadata.

bweapons_api/api.lua

@@ -406,28 +406,58 @@ function bweapons.register_weapon(def)
             end
 
             if def.has_durability then
-                local meta = minetest.deserialize(itemstack:get_metadata())
-                if
-                def.requires_technic and not meta or
-                def.requires_technic and meta.charge < technic_charge_per_use or
-                not def.requires_technic and def.custom_charge and (65535 - itemstack:get_wear()) < (65535 / uses)
-                then
+                local reload = false
+
+                if def.requires_technic then
+                    -- Technic Plus Beta
+                    if technic.use_RE_charge ~= nil then
+                        if not technic.use_RE_charge(itemstack, technic_charge_per_use) then
+                            reload = true
+                        end
+                    else
+                        -- Technic Plus
+                        local meta = itemstack:get_meta()
+                        local old_metadata = minetest.deserialize(meta:get_string(""))
+                        local charge = old_metadata.charge
+                        -- Technic
+                        if not charge then
+                            charge = meta:get_int("technic:charge")
+                        end
+
+                        if charge < technic_charge_per_use then
+                            reload = true
+                        else
+                            if not technic.creative_mode then
+                                charge = charge - technic_charge_per_use
+                                technic.set_RE_wear(itemstack, charge, technic_charge)
+                                if old_metadata.charge then
+                                    old_metadata.charge = charge
+                                    meta:set_string("", minetest.serialize(old_metadata))
+                                else
+                                    meta:set_int("technic:charge", charge)
+                                end
+                            end
+                        end
+                    end
+
+                -- Not Technic
+                else
+                    if def.custom_charge and (65535 - itemstack:get_wear()) < (65535 / uses) then
+                        reload = true
+                    else
+                        local wear = itemstack:get_wear()
+                        wear = wear + (65535/uses)
+                        if def.custom_charge and wear > 65535 then wear = 65535 end
+                        itemstack:set_wear(wear)
+                    end
+                end
+
+                if reload then
                     if def.reload_sound then
                         minetest.sound_play(def.reload_sound, {object=user, gain=reload_sound_gain, max_hear_distance=2*64})
                     end
                     return
                 end
-
-                if def.requires_technic then
-                    meta.charge = meta.charge - technic_charge_per_use
-                    technic.set_RE_wear(itemstack, meta.charge, technic_charge)
-                    itemstack:set_metadata(minetest.serialize(meta))
-                else
-                    local wear = itemstack:get_wear()
-                    wear = wear + (65535/uses)
-                    if def.custom_charge and wear > 65535 then wear = 65535 end
-                    itemstack:set_wear(wear)
-                end
             end
 
             if def.ammo_type then