Directly upload files after selection in repo index view

At the moment the user uploads files with the "browse to upload" link in the index view of a repo. After he clicked on OK/Done in the file chooser, he has to click "add" in Repomaker again for the files to be uploaded.

I propose to directly upload the files without asking for further confirmations. This can be only done with JS, so we need a fallback in case it's not available which could be the an unstlyed field which offers the current possibilities (select and click "add").

Alternatives to directly uploading are:

• Show "add" button firstly after files got selected
• Additional to the one above: Show the filenames of the selected files

Related to #47 (closed).