title: unable to compile GLSL shaders on Qt 5.3 after Nvidia driver update
body: <p>I have some very basic openGL shader that used to compile but are not compiling anymore after a Nvidia driver update.
  Every shader begins with following line:
      #version 150 core
       ....</p>
  
  <p>I used to compile those shaders using QGLShaderProgram::addShaderFromSourceFile method</p>
  
  <p>it is mentionned in documentation (<a href="http://doc.qt.digia.com/qt-5.1/qtgui/qopenglshaderprogram.html#writing-portable-shaders" rel="nofollow">http://doc.qt.digia.com/qt-5.1/qtgui/qopenglshaderprogram.html#writing-portable-shaders</a>) that for reusability purpose, following preprocessor directive are added at the beginning of the shader</p>
  
  <pre><code>#define highp
  #define mediump
  #define lowp
  </code></pre>
  
  <p>However, since the driver update, I have a compilation error:</p>
  
  <pre><code>error C0204: version directive must be first statement and may not be repeated
  </code></pre>
  
  <p>and my shader source has become</p>
  
  <pre><code>#define highp
  #define mediump
  #define lowp
  #version 150 core
   ....
  </code></pre>
  
  <p>So the issue is pretty simple to understand, however the fix is not so easy.
  Is it a way to prevent Qt to had the #define?
  What is the proper solution to deal with this issue (if possible without rewriting all my shader management code)</p>