Alternative diff rendering options

[xfbs]

Some different options for rendering the diffs:

• Side-by-side mode (easier to read files that way, but takes more screen width)
• Collapse non-changed regions (easier to skim changes that way)
• Show word/byte diff, as in this (this helps to blend out meaningless changes, such as different newline characters).

[xfbs]

Implementation-wise, I think the best UX for this would be to have two buttons in the top-right corner of the file view:

With some appropriate icons, such that you can switch between the inline and side-by-side mode.
Maybe there could also be a button to filter out Windows weirdness (using \r\n as newline character).