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/blend/blend.cpp

@@ -29,9 +29,6 @@ BlendNode::BlendNode()
   blend_input_ = new NodeInput("blend_in");
   blend_input_->set_data_type(NodeParam::kTexture);
   AddParameter(blend_input_);
-
-  texture_output_ = new NodeOutput("tex_out");
-  AddParameter(texture_output_);
 }
 
 QString BlendNode::Category() const
@@ -49,7 +46,8 @@ NodeInput *BlendNode::blend_input() const
   return blend_input_;
 }
 
-NodeOutput *BlendNode::texture_output() const
+void BlendNode::Retranslate()
 {
-  return texture_output_;
+  base_input_->set_name(tr("Base"));
+  blend_input_->set_name(tr("Blend"));
 }