lualoader: Output "Failed to parse" messages

I can't find any good reason these aren't enabled, so enable them.

The silent runs will only return false on actual parse errors, so it's ok to
be loud about those failures.

stand/lua/config.lua

@@ -423,17 +423,18 @@ function config.load(file)
 	end
 
 	if not config.parse(file) then
-		-- XXX TODO: Why is this commented out?
---		print("Failed to parse configuration: '" .. file .. "'")
+		print("Failed to parse configuration: '" .. file .. "'")
 	end
 
 	local f = loader.getenv("loader_conf_files")
 	if f ~= nil then
 		for name in f:gmatch("([%w%p]+)%s*") do
-			if not config.parse(name) then
-				-- XXX TODO: Ditto the above
---				print("Failed to parse configuration: '" ..
---				    name .. "'")
+			-- These may or may not exist, and that's ok. Do a
+			-- silent parse so that we complain on parse errors but
+			-- not for them simply not existing.
+			if not config.parse(name, true) then
+				print("Failed to parse configuration: '" ..
+				    name .. "'")
 			end
 		end
 	end