Adding experimental arguments to nmcli tool

["Fernando F. Mancera" <ffmancera riseup net>]

Hello everyone!

It has been considered to add experimental new arguments to 'nmcli' tool 
related to keyfiles. These arguments will be added with a warning 
message on documentation specifying they are experimental. The main idea 
is to experiment and not commit to them for a long time.

The current user stories that we have is:

As a Linux administrator I want to be able to use nmcli to output 
keyfiles of current profiles in stdout.

As a Linux administrator I want to be able to use nmcli to add a 
connection without NetworkManager daemon running so the new connection 
keyfile will be output in stdout instead.

The proposed experimental solutions are:

1. 'nmcli c show --keyfile $UUID' to output the profile keyfile in stdout.
2. 'nmcli c add ... --keyfile' to output the generated keyfile in stdout 
instead of adding it to the NetworkManager configuration so the 
NetworkManager daemon is not required..

What do you think about adding experimental solutions? Do you have any 
suggestions for the arguments proposed? Do you have any user story/use 
case on your mind for this feature?

Thanks!
Fernando.