updated licensing and added submodules hook

pre-commit/submodules

@@ -0,0 +1,10 @@
+#!/bin/sh
+
+# This work is marked with CC0 1.0. To view a copy of this license, visit
+# <http://creativecommons.org/publicdomain/zero/1.0>.
+
+# Git hook to update submodules to their latest versions before committing
+# changes, good for monorepos constructed from various other repositories.
+
+git submodule foreach 'git pull'
+git add