This change adds a "[Expand]" link to the "n lines hidden" bars in the diff viewer that, when clicked, will replace the bar with the contents of that chunk. There's no way to collapse again aside from reloading the page, but it's probably not a major problem in practice, and keeps the UI from being too cluttered.

Any comment flags in the chunk being expanded will be displayed. Also fixed a bug where there was an infinite loop when trying to load a collapsed diff view when a comment existed in a collapsed region.

Loaded a diff and went around expanding sections. Placed some comments in the now expanded areas and in actual changed areas. Reloaded the page to re-collapse all chunks and saw only the comment flags that should be visible. Expanded the collapsed sections and saw the other command flags display.