rewrote renderers where necessary for new node structure

Largely conforming renderers to new NodeValue system. Code seems a lot cleaner
this way which is a nice advantage. Likely non-functional as this won't
compile just yet and still needs probably another day or two of testing to get
it back to where it was before.

app/node/value.h

@@ -37,6 +37,8 @@ public:
 
   bool isEmpty() const;
 
+  static NodeValueTable Merge(QList<NodeValueTable> tables);
+
 private:
   QVariant GetInternal(const NodeParam::DataType& type, const QString& tag, bool remove);