Fix bug for chrome and refactoring and add management of the file uploaded in submission

I guys, 
with this PR the code works with Chrome, while IE10 contains a bug with large files (IE10 try to download the JSON response). I have also implemented the code to manage the file uploaded see https://github.com/lap82/DSpace/compare/EKT:DS-1252-bte...DS-1252-bte?expand=1#diff-95b1c1a8866c6f9b7aaca6d40226a863R212
If it is a bad code feel free to mantain your solution.