title: Property does not exist error in checkstyle configuration file
body: <p>I create an Android project using Android Studio. In the <code>build.gradle</code> of the app add:</p>
  
  <pre><code>apply from: '../config/quality.gradle'
  </code></pre>
  
  <p>Then I create the <code>config</code> dir with two files: <code>quality.gradle</code> like:</p>
  
  <pre><code>apply plugin: 'checkstyle'
  
  task checkstyle(type: Checkstyle) {
      configFile file("${project.rootDir}/config/checkstyle.xml")
      source 'src'
      include '**/*.java'
      exclude '**/gen/**'
      classpath = files()
  }
  </code></pre>
  
  <p>And <code>checkstyle.xml</code> like:</p>
  
  <pre><code>&lt;?xml version="1.0"?&gt;
  &lt;!DOCTYPE module PUBLIC
      "-//Puppy Crawl//DTD Check Configuration 1.3//EN"
      "http://www.puppycrawl.com/dtds/configuration_1_3.dtd"&gt;
  
  &lt;module name="Checker"&gt;
  
      &lt;module name="TreeWalker"&gt;
  
          &lt;module name="NeedBraces"&gt;
              &lt;property name="tokens" value="LITERAL_CASE, LITERAL_DEFAULT"/&gt;
              &lt;property name="allowSingleLineStatement" value="true"/&gt;
          &lt;/module&gt;
  
      &lt;/module&gt;
  
  &lt;/module&gt;
  </code></pre>
  
  <p>Running <code>gradle checkstyle</code> gives me following error:</p>
  
  <pre><code>Executing external task 'checkstyle'...
  :app:checkstyle FAILED
  
  FAILURE: Build failed with an exception.
  
  * What went wrong:
  Execution failed for task ':app:checkstyle'.
  &gt; Unable to create a Checker: cannot initialize module TreeWalker - Property 'allowSingleLineStatement' in module NeedBraces does not exist, please check the documentation
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
  
  BUILD FAILED
  </code></pre>
  
  <p>If I remove line:</p>
  
  <pre><code>&lt;property name="allowSingleLineStatement" value="true"/&gt;
  </code></pre>
  
  <p>it works. But reading the <a href="http://checkstyle.sourceforge.net/config_blocks.html#NeedBraces" rel="noreferrer">documentation</a>, first version should work too.</p>
  
  <p>It happens similar with:</p>
  
  <pre><code>&lt;module name="EmptyCatchBlock"&gt;
      &lt;property name="exceptionVariableName" value="expected|ignore"/&gt;
  &lt;/module&gt;
  </code></pre>
  
  <p>that throws me: </p>
  
  <pre><code>* What went wrong:
  Execution failed for task ':app:checkstyle'.
  &gt; Unable to create a Checker: cannot initialize module TreeWalker - Unable to instantiate EmptyCatchBlock
  </code></pre>
  
  <p>What am I doing wrong or in what way am I missunderstanding the docs?</p>