Diff of removing trailing whitespace is confusing

[ianhi]

If you have a diff that only removes trailing whitespace it is a bit confusing because on first inspection the two lines look the same:

[Carreau]

Yep +1 to that.

Either this can be fixed in Pygments's DiffLexer,
or instead of just generating the diff text and highlighting it, we could directly iterate through the diff's Operations and be smarter about the highlighting.

Or if you find another diff-highlighting engine that does it, that woudl be great.