Introduce GraphSON 4.0 and GraphBinary 2.0

Now that we have untyped GraphSON consistently implemented, there are a few things we could do to improve the untyped version and to adjust a thing or two in the typed version. Also, if we make some of these changes to GraphSON they should also apply to GraphBinary.

1. allow for multi-label on vertices as more graphs are allowing that these
days.
2. in GraphSON untyped use our "~" prefix for any structural/reserved keys like T.label or T.id
3. get the Tree right for GraphSON

{
"node": {},
"children": [{
"node": {},
"children": []
},
{
"node": {},
"children": []
},
{
"node": {},
"children": [{
"node": {},
"children": []
}]
}]
}

4. Drop extended types from GraphBinary and GraphSON and any types that might be considered JVM oriented.