removed all dependence on NodeOutputs

If Nodes only have the one output, we don't need to do so much differentiation
between them. Previous iteration used outputs as like a distinct function
within a Node (e.g. length output would return one result, buffer output would
produce a different result - each run different code to produce their results).
Now in this iteration, it's more accurate to say a Node is just one function
(which seems more appropriate for a node system anyway).

app/node/output.cpp

@@ -31,3 +31,12 @@ NodeParam::Type NodeOutput::type()
 {
   return kOutput;
 }
+
+QString NodeOutput::name()
+{
+  if (name_.isEmpty()) {
+    return tr("Output");
+  }
+
+  return NodeParam::name();
+}