Added in some display for the node_info

And cleaned up a couple of things.
Started on the pretty printing of some of the Monerod stuff

src/monero_rpc.rs

@@ -51,5 +51,15 @@ pub struct NodeInfoInner {
     was_bootstrap_ever_used: bool,
     white_peerlist_size: u64,
     wide_cumulative_difficulty: String,
-    wide_difficulty: String
+    wide_difficulty: String,
+    #[serde(skip_deserializing, default = "none")]
+    time_up_pretty: Option<String>,
+    #[serde(skip_deserializing, default = "none")]
+    space_left_pretty: Option<String>,
+    #[serde(skip_deserializing, default = "none")]
+    db_size_pretty: Option<String>,
+}
+
+fn none() -> Option<String> {
+    None
 }