Log warning of unused mods when dependencies are missing

hazmat_suit/depends.txt

@@ -1,2 +1,2 @@
 3d_armor
-technic
+technic?

hazmat_suit/init.lua

@@ -1,3 +1,8 @@
+if not minetest.get_modpath("technic") then
+	minetest.log("warning", "hazmat_suit: Mod loaded but unused.")
+	return
+end
+
 local part_count = 4
 
 local level = 35

technic_armor/depends.txt

@@ -1,3 +1,3 @@
 3d_armor
-technic_worldgen
+technic_worldgen?
 moreores?

technic_armor/init.lua

@@ -1,3 +1,8 @@
+if not minetest.get_modpath("technic_worldgen") then
+	minetest.log("warning", "technic_armor: Mod loaded but unused.")
+	return
+end
+
 local stats = {
 	lead = { name="Lead", material="technic:lead_ingot", armor=1.6, heal=0, use=500, radiation=80*1.1 },
 	brass = { name="Brass", material="technic:brass_ingot", armor=1.8, heal=0, use=650, radiation=43 },