Summary: Ref T13513. Currently: - If you click the "Show Changeset" button, your state change doesn't actually get saved on the server. - It's hard to select a changeset path name for copy/paste because the "highlight the header" code tends to eat the event. Instead: persist the former event; make the actual path text not be part of the highlight hitbox. Test Plan: - Clicked "Show Changeset", reloaded, saw changeset visibility persisted. - Selected changeset path text without issues. - Clicked non-text header area to select/deselect changesets. Maniphest Tasks: T13513 Differential Revision: https://secure.phabricator.com/D21236