diffs are hard to read because of small window size

[Igor]

sometimes, update manager needs to resolve conflicts in config files, and then it shows the user a diff of the old and new file. this is good; however, the diff is opened in a small window which makes the changes difficult to read.

often, i've only changed one or two things in a config file, and i'd like to use the new file but re-insert my changes. scrolling around side to side and up and down to find my changes is quite difficult.

in particular, it would be great if the window could get wider, as side-to-side scrolling is especially annoying.