Enhancement: Enable multiple file select

[GoogleCodeExporter]

What steps will reproduce the problem?
1. Scan anything
2. Go to "File" listing [bottom pane]
3. Use <CTL><mouse-button>

What is the expected output? What do you see instead?
Expect to select more than one file
2nd file selected, first file deselected
What version of the product are you using? On what operating system?
Using 1.7 build 20130303.214314
Using Windows 7 Service Pack 1
Please provide any additional information below.

Original issue reported on code.google.com by [email protected] on 27 Feb 2014 at 4:32