Deprecate "excerpt view" in list screen (posts, media etc)

[markkap]

The view is "list" by default with the option to show excerpt as well is hidden under the screen options. This can serve as a testament that not many think that toggling the view is worthwhile.

In addition, excerpts, as used in WordPress, are just overly reused and therefore it is hard to make them useful in all the contexts they are being used. It seems unlikely that an excerpt is going to add any useful information for the admin and editor that the title and terms do not give.