title: Hide ActionBar title just for one activity
body: <p>If I apply theme for whole application it hides ActionBar title successfully:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;resources&gt;
  &lt;style name="AppTheme" parent="@android:style/Theme.Holo.Light"&gt;
      &lt;item name="android:actionBarStyle"&gt;@style/ActionBarStyle&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;style name="ActionBarStyle" parent="@android:style/Widget.Holo.Light.ActionBar.Solid"&gt;
      &lt;item name="android:displayOptions"&gt;showHome|useLogo&lt;/item&gt;
  &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p><strong>assign in manifest</strong>:</p>
  
  <pre><code>    &lt;application
      android:name="myapp"
      android:allowBackup="true"
      android:icon="@drawable/action_bar_icon"
      android:label="@string/app_name"
      android:theme="@style/AppTheme" &gt;
  </code></pre>
  
  <p>I need ActionBar title hidden just in <strong>one activity</strong>.</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;resources&gt;
  &lt;style name="AppTheme" parent="@android:style/Theme.Holo.Light"&gt;
   ...other things...
  &lt;/style&gt;
  
  &lt;style name="MainActivityTheme" parent="@android:style/Theme.Holo.Light"&gt;
      &lt;item name="android:actionBarStyle"&gt;@style/ActionBarStyle&lt;/item&gt;
  &lt;/style&gt;
  
  &lt;style name="ActionBarStyle" parent="@android:style/Widget.Holo.Light.ActionBar.Solid"&gt;
      &lt;item name="android:displayOptions"&gt;showHome|useLogo&lt;/item&gt;
  &lt;/style&gt;
  &lt;/resources&gt;
  </code></pre>
  
  <p><strong>setting this theme explicitly for one activity:</strong></p>
  
  <pre><code>&lt;LinearLayout     xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     tools:context=".MainActivity"
     android:id="@+id/mainLayout"
     android:orientation="vertical"
     android:theme="@style/MainActivityTheme"&gt;
  </code></pre>
  
  <p>and it still shows title in <code>MainActivity</code> <code>ActionBar</code>. I know how to hide the title in java, I need to know what I do wrong here in XML.</p>