Fix a bug where, if you used the bookmarklet to upload a file, and you clicked on the back button on the upload tagging page, then you would be taken back to the upload page, which would autosubmit the upload again. Now if you click the back button on the upload tagging page, you'll be taken back to the page where you used the bookmarklet, not the upload page.
Components
Components are used to encapsulate common UI widgets used throughout the site. This includes things like comments, tag lists, post thumbnails, paginators, and other things used repeatedly throughout the site. Components encapsulate a widget's HTML, CSS, and Javascript together so that all the code for a component is in a single place.
This uses the ViewComponent library.
Components are similar in concept to React components.