* Fix up is_amount to handle floats for SOL; expand amount_of test
* Use required_lamports_from and is_amount across CLI
* Remove obsolete test (now handled by clap)
--gossip-port now specifies exactly that, the gossip port to use. The
new --gossip-host argument can be used to specify the DNS name/IP
address for gossip if --entrypoint is not supplied (when --entrypoint is
supplied, the gossip address is automatically set to the node's ip
address as observed by the entrypoint)