Add varshort data type

[deathcap]

Extended 'short' type, see http://wiki.vg/Minecraft_Forge_Handshake#Definitions

With this PR and minecraft-data 1.7 plugin_channel 0x3f updated to varshort, able to login to an FTBInfinityServer-2.3.5-1.7.10 server (although it later crashes due to use of other custom packets)

ref PrismarineJS/node-minecraft-protocol-forge#7

Closes PrismarineJS/node-minecraft-protocol-forge#1 (couldn't make the change in nmp-f because it requires changing the protocol definition in minecraft-data unfortunately, but it is backwards-compatible with vanilla 1.7)

[rom1504]

Can you add it in https://github.com/roblabla/ProtoDef/blob/master/doc/datatypes.md#utils ?

[deathcap]

Added

[rom1504]

I'm not 100% sure whether this should be in ProtoDef or in nmp though. Does this exist anywhere but in minecraft protocol ?

[rom1504]

Now that nmp has a customPackets option, this could even move to nmp-forge.

We can always move things to nmp or protodef if it's useful in general anyway.

Or can you think of an other thing that forge that would use this ?

[rom1504]

(trying not to bloat protodef with too many default types)

[roblabla]

stop

Could we please have generalized varnum that takes the maximum number of bytes as arguments ? Instead of bloating protodef with more and more and more types that do exactly the same thing...

[deathcap]

No varshort is completely different than varint/varlong despite the similar name. It's backwards-compatible with short for positive values, and for negative adds an extra byte.

But to rom's point, I think it would make sense to move this to nmp-forge, as that is all that uses it (Forge invented this "varshort" data type): PrismarineJS/node-minecraft-protocol-forge#1 (though I'll need some means to modify the 0x3f packet definition before passed to the serializer)

[rom1504]

seems like we haven't needed this
if someone need this one day, he can reopen