Readd tar block. Fixes #103

The proper way to resolve the redundancy between `building_blocks:Tar` and `moreblocks:tar` is with an alias in building_blocks as noted in issue #68.

The recipe conflict with streetsmod has been resolved by using `default:pine_tree` in place of `default:gravel`.  This may also be more realistic than gravel as a source of tar because pine derived tar was once of major economic importance.

aliases.lua

@@ -62,7 +62,6 @@ minetest.register_alias("moreblocks:wood_tile_left","moreblocks:wood_tile_up")
 minetest.register_alias("moreblocks:wood_tile_right","moreblocks:wood_tile_up")
 minetest.register_alias("moreblocks:empty_bookshelf","moreblocks:empty_shelf")
 minetest.register_alias("moreblocks:split_stone_tile_alt","moreblocks:checker_stone_tile")
-minetest.register_alias("moreblocks:tar","default:gravel")
 
 -- ABM for horizontal trees (fix facedir):
 local horizontal_tree_convert_facedir = {7, 12, 9, 18}

crafting.lua

@@ -485,6 +485,10 @@ minetest.register_craft({
 	}
 })
 
+minetest.register_craft({
+	type = "cooking", output = "moreblocks:tar", recipe = "default:pine_tree",
+})
+
 minetest.register_craft({
 	type = "shapeless",
 	output = "moreblocks:copperpatina",

nodes.lua

@@ -113,6 +113,12 @@ local nodes = {
 		is_ground_content = false,
 		sounds = sound_stone,
 	},
+	["tar"] = {
+		description = S("Tar"),
+		groups = {cracky=2, tar_block=1},
+		is_ground_content = false,
+		sounds = sound_stone,
+	},
 	["dirt_compressed"] = {
 		description = S("Compressed Dirt"),
 		groups = {crumbly=2},