Recognize Visual Studio 2013 with Update 2.
Minimize main window into the notification area ("systray"), when trying to close the program while we still have running jobs.
Made the file size estimation less jumpy: Before the progress was rounded to a precision of 1.0 percent. This caused a "jump" of the estimated size each time the integral part of progress increased by one. Now the progress is rounded to a precision of 0.1 percent, which greatly reduces the effect. Furthermore, we apply a slight smoothing filter on the estimated values in order to make the output more "stable".