Logging for prekey fetches, load of log files (#1836)

* Log the files discovered in logPath

I've encountered some logs which include very old entries; and my
suspicion is that we're not cleaning up old log files properly.

* Log prekey fetches (success and failure), just like signed keys

* Force log file information into the final web-ready log

app/logging.js

@@ -93,8 +93,19 @@ function fetch(logPath) {
     return path.join(logPath, file)
   });
 
+  // creating a manual log entry for the final log result
+  var now = new Date();
+  const fileListEntry = {
+    level: 30, // INFO
+    time: now.toJSON(),
+    msg: 'Loaded this list of log files from logPath: ' + files.join(', '),
+  };
+
   return Promise.all(paths.map(fetchLog)).then(function(results) {
     const data = _.flatten(results);
+
+    data.push(fileListEntry);
+
     return _.sortBy(data, 'time');
   });
 }

js/signal_protocol_store.js

@@ -186,11 +186,15 @@
             var prekey = new PreKey({id: keyId});
             return new Promise(function(resolve) {
                 prekey.fetch().then(function() {
+                    console.log('Successfully fetched prekey:', keyId);
                     resolve({
-                        pubKey: prekey.attributes.publicKey,
+                        pubKey: prekey.get('publicKey'),
-                        privKey: prekey.attributes.privateKey
+                        privKey: prekey.get('privateKey'),
                     });
-                }).fail(resolve);
+                }, function() {
+                    console.log('Failed to load prekey:', keyId);
+                    resolve();
+                });
             });
         },
         storePreKey: function(keyId, keyPair) {