don't police data type connections between nodes

Nodes were previously written to be "strongly typed" in that a parameter's
"type" enforced whether it could be connected to another. All code related
to that has now been removed since not only is it hard to maintain and
likely unnecessary, it's possible the nodes will work differently later on
anyway.

app/node/input.cpp

@@ -39,14 +39,23 @@ NodeParam::Type NodeInput::type()
   return kInput;
 }
 
-void NodeInput::add_data_input(const NodeParam::DataType &data_type)
+QString NodeInput::name()
 {
-  inputs_.append(data_type);
+  if (name_.isEmpty()) {
+    return GetDefaultDataTypeName(data_type());
+  }
+
+  return NodeParam::name();
 }
 
-bool NodeInput::can_accept_type(const NodeParam::DataType &data_type)
+const NodeParam::DataType &NodeInput::data_type()
 {
-  return AreDataTypesCompatible(data_type, inputs_);
+  return data_type_;
+}
+
+void NodeInput::set_data_type(const NodeParam::DataType &type)
+{
+  data_type_ = type;
 }
 
 NodeOutput *NodeInput::get_connected_output()
@@ -163,27 +172,6 @@ void NodeInput::set_maximum(const QVariant &max)
   has_maximum_ = true;
 }
 
-NodeParam::DataType NodeInput::data_type()
-{
-  if (IsConnected()) {
-    // Return the connected output's data type
-    return edges_.first()->output()->data_type();
-  }
-
-  if (inputs_.isEmpty()) {
-    // Safety if no inputs have been added
-    return kNone;
-  }
-
-  // Return first
-  return inputs_.first();
-}
-
-const QList<NodeParam::DataType> &NodeInput::inputs()
-{
-  return inputs_;
-}
-
 void NodeInput::CopyValues(NodeInput *source, NodeInput *dest)
 {
   // Copy values