title: CheckBox doesn't appear in CheckedTextView
body: <p>When I set up my <code>CheckedTextView</code>, it has no <code>CheckBox</code>. Here is the xml code for it:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
          android:orientation="horizontal"
          android:layout_width="fill_parent"
          android:layout_height="fill_parent"
          &gt;
      &lt;CheckedTextView
              android:id="@+id/checkedtext"
              android:layout_width="wrap_content" 
              android:layout_height="wrap_content"
              android:layout_alignParentLeft="true"
              android:checked="false"
              android:textSize="25dp"
              android:textColor="#FFFFFF"
              android:checkMark="@android:attr/checkMark"
              /&gt;
  &lt;/RelativeLayout&gt;
  </code></pre>