Create form to ask for confirmation of delete

This form will be shown when the user tries to delete a file from the disk from within the program.

* Add form to ask the user if they are sure they want to delete the file

![Delete_Confirm](https://f.cloud.github.com/assets/5778739/1747501/87572276-645d-11e3-9a0a-2fc12841b96c.png)