Add submodule url

.gitmodules

@@ -793,3 +793,8 @@
 	url = ../property_map_parallel.git
 	fetchRecurseSubmodules = on-demand
 	branch = .
+[submodule "url"]
+	path = libs/url
+	url = ../url.git
+	fetchRecurseSubmodules = on-demand
+	branch = .

libs/url

@@ -0,0 +1 @@
+Subproject commit 65f3e0f0648e7ae02684d05994c6655d3668b994