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

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

 <h1>Declare Permissions</h1>
 
 <p>
 To use most chrome.* APIs,
 your extension or app must declare its intent in the
 "permissions" field of the
 <a href="manifest.html">manifest</a>.
 Each permission can be either one of a list of known strings
 (such as "geolocation")
 or a <a href="match_patterns.html">match pattern</a>
@@ skipping 221 matching lines @@
        without calling permission methods
        (such as <code>checkPermission()</code>).
        For more information see
        <a href="notifications.html">Desktop Notifications</a>.</td>
 </tr>
 {{?is_apps}}
 <tr>
   <td> "pointerLock" </td>
   <td> Required to use
     <a href="http://www.w3.org/TR/pointerlock/">Pointer Lock</a> via calls to
-    <code>webkitRequestPointerLock</code></a> or Pepper's
+    <code>webkitRequestPointerLock</code> or Pepper's
     <a href="https://developers.google.com/native-client/peppercpp/classpp_1_1_mouse_lock">
     Mouse Lock API</a>. </td>
 </tr>
 {{/is_apps}}
 {{^is_apps}}
 <tr>
   <td> "privacy" </td>
   <td> Required if the extension uses the
        <a href="privacy.html">chrome.privacy</a> module. </td>
 </tr>
@@ skipping 62 matching lines @@
 </tr>
 <tr>
   <td> "webRequestBlocking" </td>
   <td> Required if the extension uses the
        <a href="webRequest.html">chrome.webRequest</a> module in a blocking
        fashion. </td>
 </tr>
 {{/is_apps}}
 </tr>
 </table>