Add 5 commands

[SamsungGalaxyPlayer]

--proxy with good description.

--rpc-payment commands with descriptions straight from command line.

Change title of Monero network for clarity that it's for picking which blockchain to use.

[nahuhh]

Just a heads up Line 143 (and anywhere else) --add-peer (and --add-priority-node) is no longer needed for onion/i2p. It was fixed at or just before hard fork