Compiling.

Need to see if I can do a generic implemented of IntoBoxedContextElement for all objects implementing Copy, and I need to implement the compare code to make sure this all works before I start integrating this more.

src/bin.rs

@@ -1,5 +1,6 @@
 extern crate nom;
 
+use crate::renderer::IntoBoxedContextElement;
 use parser::Filter;
 use renderer::compile_template;
 use renderer::CompiledTemplate;
@@ -137,3 +138,9 @@ impl Loopable for serde_json::Value {
         }
     }
 }
+
+impl IntoBoxedContextElement for serde_json::Value {
+    fn clone_to_box(&self) -> Box<dyn ContextElement> {
+        Box::new(self.clone())
+    }
+}