Try to use the new version of Protobuf to read vector map tiles

[asinghvi17]

I just tried it on Mapbox's test cases and it seems to work.

Now, the only remaining blockers to displaying vector map tiles are:

• we need to translate all of this to a usable format,
• we need a plot recipe for it,
• we need some way to apply tile style sheets to this, otherwise it will be impossible to actually use.