Add links to MP and resolve minor fixes

appengine/swarming/elements/res/imp/botpage/bot-page-data.html

 <!--
   Copyright 2016 The LUCI Authors. All rights reserved.
   Use of this source code is governed under the Apache License, Version 2.0
   that can be found in the LICENSE file.
 
   This in an HTML Import-able file that contains the definition
   of the following elements:
 
     <bot-page-data>
 
@@ skipping 124 matching lines @@
         }, BOT_ID_DEBOUNCE_MS);
 
       },
 
       _parseBot: function(bot) {
         if (!bot) {
           return {};
         }
         // Do any preprocessing here
         bot.state = bot.state || "{}";
-        bot.state = JSON.parse(bot.state);
+        bot.state = JSON.parse(bot.state) || {};
 
         // get the disks in an easier to deal with format, sorted by size.
         var disks = bot.state.disks || {};
         var keys = Object.keys(disks);
         if (!keys.length) {
           bot.disks = [{"id": "unknown", "mb": 0}];
         } else {
           bot.disks = [];
           for (var i = 0; i < keys.length; i++) {
             bot.disks.push({"id":keys[i], "mb":disks[keys[i]].free_mb});
@@ skipping 82 matching lines @@
           return b.started_ts - a.started_ts;
         });
 
         return tasks;
       }
 
     });
   })();
   </script>
 </dom-module>