Fix some typos, broken links and other issues in extension docs

chrome/common/extensions/docs/templates/articles/api_other.html

 <h1>Other APIs</h1>
 
 <p>
 In addition to the
 <a href="api_index.html">chrome.* APIs</a>,
 extensions can use all the APIs
 that the browser provides
 to web pages and apps.
 If the browser doesn't support an API you want to use,
 you can bundle additional API libraries into your extension.
 </p>
 
 <p>Here's a sampling of the APIs that extensions can use:</p>
 
 <dl>
 <dt><strong> Standard JavaScript APIs </strong></dt>
 <dd> These are the same core JavaScript and
   <a href="https://developer.mozilla.org/en/Gecko_DOM_Reference">Document Object Model</a>
   (DOM) APIs
   that you can use in ordinary web apps.
   
 <!-- Use onclick in your toolbar div to add click behavior.
 E.g. window.open(someUrl). --></dd>
 <dt><strong> XMLHttpRequest </strong></dt>
 <dd>
   Use <a href="xhr.html">XMLHttpRequest</a>
   to request data from one or more servers.
-  The <a href="manifest.html#permissions">permissions</a> field
+  The <a href="declare_permissions.html">permissions</a> field
   of the manifest specifies
   which hosts the extension can send requests to.
   </dd>
 <dt> <strong>HTML5 and other emerging APIs</strong></dt>
 <dd> Google Chrome supports HTML5 features,
      along with other emerging APIs.
      Here are some of the APIs you can use:
   <ul>
   <li> audio
     (<a href="http://www.html5rocks.com/tutorials/audio/quick/">tutorial</a>) </li>
@@ skipping 38 matching lines @@
 </dd>
 <dt><strong> V8 APIs</strong>, such as<strong> JSON </strong></dt>
 <dd> Because JSON is in V8, you don't need to include a JSON library to use JSON functions. </dd>
 <dt><strong>APIs in bundled libraries</strong></dt>
 <dd> If you want to use a library that the browser doesn't provide
 (for example, jQuery),
 you can bundle that library's JavaScript files with your extension.
 Bundled libraries work in extensions
 just as they do in other web pages.
 </dd>
-</dl>
+</dl>