Add submodule assert to master

.gitmodules

@@ -450,3 +450,7 @@
 	path = libs/lockfree
 	url = ../lockfree.git
 	fetchRecurseSubmodules = on-demand
+[submodule "assert"]
+	path = libs/assert
+	url = ../assert.git
+	fetchRecurseSubmodules = on-demand

libs/assert

@@ -0,0 +1 @@
+Subproject commit 69590ce1683ca836fe61bb0a82d9e142e001de66