Enable commit.expandAllFiles by default

[rchl]

I think commit.expandAllFiles option should be enabled by default. That is because I think it's not obvious that clicking the file names in the commit view does something. Making things more obvious would be another option.

[jensl]

I seldom click the file names when reviewing; I just press space to display the next file, scroll down one page, and mark the previous file as reviewed, all in one. So I would certainly want commit.expandAllFiles off, but then I could just disable it. Agree on obviousness. Too bad I'm not exactly a UI designer. :-)

There's also a technical reason why expanding all files is not optimal; collapsed files are much less expensive in terms of DOM size (and transferred HTML size.) Whether this is a problem of course depends on the size of the diff, the browser and the system the browser runs on. There's of course commit.expandFilesLimit which (if set to a non-default value) essentially overrides commit.expandAllFiles=true if the diff is too large (in the "touches too many files" sense.)