title: R.java file is not generated in a library project
body: <p>I'm trying to use the <strong><a href="https://github.com/jfeinstein10/SlidingMenu" rel="nofollow">SlidingMenu</a></strong> library. As described, I created a new Android project using the <strong>library</strong> directory, tried "Project > Clean" to generate the R.java but doesn't work.</p>
  
  <p>The curious fact is that if I open the project properties and uncheck the "Is Library" all will work and R.java file is generated without errors. Besides the errors with the lack of R.java file, the tab "Problems" presents this:</p>
  
  <blockquote>
    <p>Unparsed aapt error(s)! Check the console for output.</p>
  </blockquote>
  
  <p>If I remove, as suggested in several responses, it appears again when I clean the project.</p>
  
  <p>I appreciate any suggestion.</p>