use uuid for identifying viewers

To aid generating a cache ID, each viewer node needs a UUID. Previous iterations
tried to hash a name and time, but a UUID is a much more efficient way to do
this.

app/render/exporter.cpp

@@ -0,0 +1,6 @@
+#include "exporter.h"
+
+Exporter::Exporter()
+{
+
+}