title: Activity theme not changing
body: <p>I have a <code>styles.xml</code> where I have defined styles</p>
  
  <pre><code>&lt;!-- =============================================================== --&gt;
  &lt;!-- Dark styles --&gt;
  &lt;!-- =============================================================== --&gt;
  
  &lt;style name = "AppBgDark"&gt;
      &lt;item name="android:background"&gt;#333333&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name = "CardBgDark"&gt;
      &lt;item name="android:background"&gt;@drawable/rounded_corners_dark&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name="event_title_dark"&gt;
      &lt;item name="android:textColor"&gt;#fff&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name="event_date_dark"&gt;
      &lt;item name="android:textColor"&gt;#fff&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name="event_location_dark"&gt;
      &lt;item name="android:textColor"&gt;#aaa&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name="event_calendar_dark"&gt;
      &lt;item name="android:textColor"&gt;#aaa&lt;/item&gt;
  &lt;/style&gt;
  &lt;style name="Actionbar_dark" parent= "Widget.Sherlock.Light.ActionBar"&gt;
       &lt;item name = "android:background"&gt;#333333&lt;/item&gt;
  </code></pre>
  
  <p>the same way for a light theme as well.
  Then i have created a  themes.xml and a attrs.xml to refference these styles.</p>
  
  <p>The problem is when i apply the references from the attrs.xml in the layout i can see no changes happening
  For example:    </p>
  
  <pre><code>&lt;LinearLayout
          android:id="@+id/cardlayout"
          style="?card_background"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          android:layout_marginLeft="7dp"
          android:layout_marginRight="7dp"
          android:orientation="vertical"
          android:padding="7dp" &gt;
  </code></pre>
  
  <p>where am I going wrong? Any suggestions? I am really confused!!!</p>