Fix crufty, CVS-driven assumptions in commitlog views

OK, first round of changes was to the 'inner view' commitlog_commit_items, to which I've added three displays since different parent views require slightly different internals, and to allow the option of having/not having the visual diffstat. The 'Defaults' view now includes just the path & lines added/removed; 'With name' uses the [name]: [path] format but is otherwise the same as Defaults; 'With diffstat' is the same as Defaults except that a 7-character visual diffstat is added at the end; 'With name & diffstat' combines exactly what each of the other two displays add.

Hacked away at other pieces here for QUITE a while and ran into some annoying roadblocks, most prominently what looks like a bug in views_field_view that prevents the non-default displays I mentioned in #1 from being used (see #1013294: Non-default displays cannot receive arguments). Nevertheless, the base views have been updated, although the interior views won't work on some of them until that issue is fixed.

I did realize that for the generic/base global commit view it might not be safe to pull the project up into the outer view as I described in the skitch, so it sticks with the old approach. It's perfectly safe for the git-specific one - which now exists - so that one does do it.