This adds a new global option to the ipa command, -f/--no-fallback. If this
is included then just the server configured in /etc/ipa/default.conf is used.
Otherwise that is tried first then all servers in DNS with the ldap SRV record
are tried.
Create a new Local() Command class for local-only commands. The help
command is one of these. It shouldn't need a remote connection to execute.
ticket #15