Allow cutting down Ethereal bamboo with chainsaw

Adds `ethereal:bamboo` into `timber_nodenames`.

This PR is ready for review.

technic/mod.conf

@@ -1,3 +1,3 @@
 name = technic
 depends = pipeworks, technic_worldgen, basic_materials
-optional_depends = mcl_core, mcl_sounds, default, bucket, mesecons, mesecons_mvps, digilines, digiline_remote, unified_inventory, dye, craftguide, i3, mtt, vizlib, moreores, mcl_buckets, mcl_explosions, mcl_craftguide
+optional_depends = mcl_core, mcl_sounds, default, bucket, mesecons, mesecons_mvps, digilines, digiline_remote, unified_inventory, dye, craftguide, i3, mtt, vizlib, moreores, mcl_buckets, mcl_explosions, mcl_craftguide, ethereal

technic/tools/chainsaw.lua

@@ -43,6 +43,10 @@ if minetest.get_modpath("trunks") then
 	end
 end
 
+if minetest.get_modpath("ethereal") then
+	timber_nodenames["ethereal:bamboo"] = true
+end
+
 local S = technic.getter
 
 -- Table for saving what was sawed down