Some variables not reset after running a view preview

I'm using hook_views_preview_info_alter() to add in some data about a view and discovered that I can't actually use $view->get_title() nor $view->get_url() as the preview code in includes/admin.inc overrides these. We should reset these back after running $view->preview() so that other code can call those functions. This is a quasi-blocker for #1278550: Add basic view tokens as performing token_replace() with a view object in preview fails the [view:title] and [view:url] tokens.