The diff file index wasn't properly updating when switching pages in a

diff. This was due to some of the work done to move diff loading into

the models. An array was no longer being cleared and the way the file

list was being repopulated resulted in a different event name being

used. This fixes both of those, allowing the file index to update

whenever the list of files changes.

Changed pages in a diff with lots of files. Saw that the file list

fully repopulated each time, updating the filenames, anchors, and

icons.