FE legacy ping support

src/ping.js implements a server list ping using ping and ping_start in the STATUS protocol state, but there is another type of ping initiated by sending the bytes 0xfe 0x01. Sometimes known as the "legacy" ping, but it supported by modern versions of Minecraft, including 1.8.9 and the 1.9 snapshots: http://wiki.vg/Protocol#Legacy_Server_List_Ping

While not technically part of the current protocol, legacy clients may send this packet to initiate Server List Ping, and modern servers should handle it correctly.

node-minecraft-protocol should support FE01 ping, in both the server and client. Server is especially important since third-party ping/status software may still send FE01 pings, due to simplicity and widespread support (vanilla servers support it). Client support would be useful when pinging servers of an unknown version, including those with the modern Netty protocol, or earlier versions (all the way back to Minecraft 1.4.4 release is supported by the FE01 ping).

Example of fe01 ping in nodejs: https://github.com/deathcap/mcping16/blob/master/mcping16.js#L124 - but needs to be cleaned up to use protodef, etc.

Start with src/ping.js and the linked wiki.vg Legacy Server List Ping specification, then compare the existing STATUS ping flow with the FE 01 packet. Use the linked mcping16.js example as a reference for the protocol details and protodef cleanup. Done means node-minecraft-protocol handles FE01 ping requests in both its server and client paths.