bug#12492: Acknowledgement (24.2.50; Open vc-dir buffer easier and faster)

[Juri Linkov]

>> C-x v / is so nicely mnemonic keybinding that it even makes sense
>> to use it as a key prefix to the whole set of root-related commands, e.g.:
>>
>> C-x v / =   vc-root-diff (mnemonic: '/' root, '=' diff)
>> C-x v / l   vc-print-root-log (mnemonic: '/' root, 'l' log)
>> C-x v / d   vc-root-dir (mnemonic: '/' root, 'd' dir)
>
> Hm...  makes sense.  But they are inconveniently long for tasks that you
> do all the time.

Also it makes more sense to introduce a root prefix map for the whole set
of project related commands (not necessarily restricted to VCS):

C-x / d - project dir
C-x / f - project find file
C-x / r - project find regexp
C-x / t - project tag search
C-x / s - project search/grep
C-x / % - project query-replace
C-x / l - project log
C-x / = - project diff
...