Display modal window for preview of the imported data

![inspire - high-energy physics literature database](https://cloud.githubusercontent.com/assets/3083746/4151698/5230e31e-3448-11e4-8894-a7e4885fb1dd.png)
![inspire - high-energy physics literature database 1](https://cloud.githubusercontent.com/assets/3083746/4151697/522d8368-3448-11e4-8fe4-b3efce92d47c.png)
The import messages, shouldn't they be shown on 'accepted' event or when when import fails only? It makes no sense to show that the import succeeded when the user rejected it.