Reconsider "falcon shell" without arguments automatically connecting to all hosts

[TannerFilip]

It seems like a strange choice to have argument-less falcon shell automatically connect to all hosts on the instance, especially when falcon profiles and falcon policies both print the help. I think it would make more sense for it to print the help information if run without arguments/options, and then require --all for it to connect to all hosts.

Since this could be a breaking change to some workflows, an alternative may be to put a(n overridable) short sleep in, so you have time to kill the process before it starts attempting to connect to the hosts.