Add option to diffEditor.wordWrap to inherit setting from the compared file

[johannespitz]

Problem: Often I toggle the word wrap for a couple of files (.tex files usually). And every time I want to view the diff, the current file is displayed with word wrap while the old file is displayed without word wrap: Then I have to toggle the word wrap for the old file by hand (which for some reason sends me to a different location in the file).

Solution: I think it would always make sense to use the same word wrap setting for both files, but adding an option to enforce this behavior would also be an excellent solution for me.