Provide interactive configuration mode

[asdil12]

In update-alternatives we have something like this:

# update-alternatives --config ftp
There are 2 choices for the alternative ftp (providing /usr/bin/ftp).

  Selection    Path            Priority   Status
------------------------------------------------------------
* 0            /usr/bin/tnftp   10        auto mode
  1            /usr/bin/lftp    10        manual mode
  2            /usr/bin/tnftp   10        manual mode

Press <enter> to keep the current choice[*], or type selection number: 

It would improve user experience to have something similar.