Add --pretend support to runscript

[davidepesa@gmail.com]

[ from  https://bugs.gentoo.org/show_bug.cgi?id=219676 ]
As discussed many months ago on IRC, please add a --pretend option to runscript.....

<snip>
[23:33:30] <Pesa> which asks the user to confirm before proceeding
[23:33:34] <Pesa> example
[23:33:51] <Pesa> if i do /etc/init.d/hald restart, xdm will be restarted too
[23:34:18] <Pesa> but the user may not know, and running that command within an X session may have undesired results
[23:34:58] <Pesa> --ask tells the user which services will be restarted, or stopped if any, and asks for confirmation
[23:35:19] <Pesa> the same applies for "start" action
[23:35:50] <Pesa> should be used like so: /etc/init.d/foo --ask <action>
[23:36:05] <rsmarples> no, i don't like that. i don't like interactiveness like that
[23:36:15] <rsmarples> how about a --pretend option instead?
[23:36:27] <Pesa> well, yes
[23:36:30] <rsmarples> it shows you the services it would start or stop if you did that
[23:36:42] <Pesa> yes, maybe it's even better
[23:36:52] <rsmarples> then you could pipe it if needed
[23:37:03] <Pesa> waiting for user input may be problematic indeed
[23:37:04] <zzam> or like emerge where --ask is --pretend + exactly one confirmation
[23:37:43] <Pesa> well, --pretend is just a --dry-run
[23:37:52] <zzam> sure
[23:38:49] <rsmarples> Pesa: file a bug asking for that at bugs.marples.name so I don't forget :)
</snip>

[roy]

Fixed in f689187966ff4339e1868094c0636b969b4eff26