Improvements to the gerrit-switch extension + Replace tabs with activeTab to reduce the number of permissions needed by the extension. + Redirect to the GWT UI version of a URL if a PolyGerrit URL is pasted but the user doesn’t have PolyGerrit turned on. Bug: Issue 3959 Bug: Issue 3924 Change-Id: I3b642d99a2a55bfa8242b678d86c8dcc11bc50c1