Add change diff page to file view, to mimic git log --patch-with-stat -- $FILE

What

Page which shows change history for a file in diff form.

UI equivalent of git log --patch-with-stat -- $FILE

Why

Serves similar purpose to blame view and commit message log, but much easier to use.

Sometimes the blame view doesn't adequately show change history. If there was a recent indentation change for example, there will be little indication of who last made a significant change to the file or what it was.

Instead a page showing diffs for each commit which touched the file in chronological order allows you to scroll past irrelevant changes and find the information you are looking for.

Currently you'd have to click through to lots of individual commits until you find the right one.