[WIP] first draft of querying UGen's signal graph connections

[nshaheed]

This is a first pass at doing this, there several problems/things to think through:

• multichannel ugens (i.e. dac) returns every individual channel ugen is attached
  for example:

SinOsc s => dac;

s.goesTo() @=> UGen arr[];

// This is two because dac is left and right
<<< arr.size() >>>;

<<< arr[0] >>>;
<<< arr[1] >>>;

• Type has no way of returning the most specific UGen, for example I can do type.is("Gain") to test if my type is a gain, but there's no way to query that information directly