Whitelist support in the cli

[WhoSoup]

This is the walletd counterpart that uses the wsapi whitelist feature in https://github.com/FactomProject/factom/pull/135.

It adds a "-whitelist" flag where people can specify remote ips to allow. Note that if someone wants to deny ALL remote connections and only allow local connections, they should use #84 instead. The whitelist would not do anything unless "-remote" is specified.

This is a draft PR that will be updated when the whitelist feature is merged and glide can be updated with the new commit.