0.2: remove bootstrap built-in iconfonts

Author: guo-yu

layout.html

@@ -25,11 +25,11 @@
 <header ng-class="state.current.controller">
   <nav>
     <div class="options pull-right">
-      <a ui-sref="layout.create" class="avatar" ng-show="user" tooltip-placement="left" tooltip="{{user.name}}" ng-cloak>
+      <a ui-sref="layout.create" class="avatar" ng-show="user" ng-cloak>
         <img ng-src="{{user.avatar_url}}" alt="{{user.name}}" class="img-circle"/>
       </a>
       <a id="signin-btn" ng-show="isVisitor" ng-click="toggleSigninSection();" tooltip-placement="left" tooltip="通过社交网络登录" href="javascript:void(0);" ng-cloak>
-        <span class='glyphicon glyphicon-off'></span>
+        <span class='fa fa-power-off'></span>
       </a>
     </div>
   </nav>