bug#16214: Consistency in dired-, occur-, and grep-mode

[Tak Kunihiro]

> I think this will be much easier for new and existing users to
> remember.

Good idea. However, to change default is another step.  I think that the
first step is (1) to write a global minor mode to provide the consistent
keymap. (2) Then install on ELPA. After a while, (3) include in main
body. (4) After a while, suggest to turn the minor mode on by default.

I cannot initiate such project now. Thus I want to post this project in
somewhere so that someone who wants to contribute Emacs can notice this.