Make strategy to determine if a sequence is vector or list pluggable

[bpsm]

As suggested by abernard in a comment on issue 32:

On the issue of this handling Guava collections, I wonder if the code to determine List or Vector should be separated out into an interface. This would be something like:

interface SequenceTypeSelector {
    boolean isVector(Object o);
}

The selector could be attached to the ProtocolBuilder for the Printer (with a default implementation provided of course). Extending SequenceTypeSelector would allow custom dispatch for types, allowing the simple if-else select on java.util.RandomAccess, or a Map lookup for more complex type hierarchies.

This was in response to a comment of mine that I was losing the list/vector distinction in edn-java-guava since guava's immutable list implementations implement RandomAccess.