Add revisions system

Conflicts:
	client/css/style.css
	views/layout.jade

lib/data/mongodb.js

@@ -49,6 +49,28 @@ db.prototype = {
 		);
 	},
 
+	// revision commands
+	setRevisions: function(room, revisions) {
+		this.rooms.update(
+			{name:room},
+			{$set:{revisions:revisions}}
+		);
+	},
+
+	getRevisions: function(room, callback) {
+		this.rooms.findOne(
+			{name:room},
+			{revisions:true},
+			function(err, room) {
+				if(room) {
+					callback(room.revisions);
+				} else {
+					callback();
+				}
+			}
+		);
+	},
+
 	// Column commands
 	createColumn: function(room, name, callback)
 	{