chore(testing): de-flake a ngHref test for navigating away from the Angular page
chore(build): Update closure i18n integration

Use git repo as source and use q-io instead of q-fs
docs(contributing): add code of conduct
fix($compile): link async+replace element transclusion directives with comment element

Previously, element transclusion directives would not receive a comment node in their
link functions when they were the root of an asynchronous replace template. This would
cause duplicate elements to appear in an ng-if expression within ng-repeat.

Closes #6006