Add message edit records + work on guilds.

src/database/message.rs

@@ -1,13 +1,22 @@
 use serde::{ Deserialize, Serialize };
 use bson::{ UtcDateTime };
 
+#[derive(Serialize, Deserialize, Debug)]
+pub struct PreviousEntry {
+    pub content: String,
+    pub time: UtcDateTime,
+}
+
 #[derive(Serialize, Deserialize, Debug)]
 pub struct Message {
     #[serde(rename = "_id")]
 	pub id: String,
+	// pub nonce: String, used internally
 	pub channel: String,
 	pub author: String,
 
 	pub content: String,
-	pub edited: Option<UtcDateTime>,
+    pub edited: Option<UtcDateTime>,
+    
+    pub previous_content: Option<Vec<PreviousEntry>>
 }