Display the content of new file in the changed section of popup window

[le-git-imate]

Description of issue or feature request
The changed section in the popup window only shows changed content of an existing file (as a result of edit operation). We should display the content of new file in the window to make sure a malicious scripts have not changed the content. This should be addressed in accordance with #22.

Current behavior

• Changed section of pop window display only changes of an edited file.

Expected behavior

• Display the content of added and uploaded files as well by updating this part of the code.