Add code for submitting debug logs

We keep the last 1000 log messages in memory and dump them to an
anonymous public gist if console.post is called.

// FREEBIE

background.html

@@ -256,6 +256,7 @@
     <button class='minimize'>&minus;</button>
     <button class='close'>&times;</button>
   </script>
+  <script type="text/javascript" src="js/debugLog.js"></script>
   <script type="text/javascript" src="js/components.js"></script>
   <script type="text/javascript" src="js/database.js"></script>
   <script type="text/javascript" src="js/storage.js"></script>

js/debugLog.js

@@ -0,0 +1,37 @@
+/*
+ * vim: ts=4:sw=4:expandtab
+ */
+(function () {
+    'use strict';
+    var MAX_MESSAGES = 1000;
+    var PHONE_REGEX = /\+\d{7,12}(\d{3})/g;
+    var debugLog = [];
+    if (window.console) {
+        console._log = console.log;
+        console.log = function(thing){
+            console._log(thing);
+            if (debugLog.length > MAX_MESSAGES) {
+                debugLog.shift();
+            }
+            var str = ('' + thing).replace(PHONE_REGEX, "+[REDACTED]$1");
+            debugLog.push(str);
+        };
+        console.get = function() {
+            return debugLog.join('\n');
+        };
+        console.post = function(log) {
+            if (log === undefined) {
+                log = console.get();
+            }
+            return new Promise(function(resolve) {
+                $.post('https://api.github.com/gists', textsecure.utils.jsonThing({
+                    "public": true,
+                    "files": { "debugLog.txt": { "content": log } }
+                })).then(function(response) {
+                    console._log('Posted debug log to ', response.html_url);
+                    resolve(response.html_url);
+                }).fail(resolve);
+            });
+        };
+    }
+})();