title: Three.js( R71 ) not working on IE11 windows 8.1
body: <p>I am running R71 of three.js and it's not working on windows 8.1 ie 11 
  version : 11.096
  Update versions 11.0.7
  I get these warnings:</p>
  
  <pre><code>THREE.WebGLRenderer: OES_texture_half_float extension not supported.
  THREE.WebGLRenderer: OES_texture_half_float_linear extension not supported.
  THREE.WebGLRenderer: OES_element_index_uint extension not supported.
  </code></pre>
  
  <p>Then shader compiler errors.</p>
  
  <p>Then a lot of :</p>
  
  <pre><code>WEBGL11057: INVALID_ENUM: drawElements: Only UNSIGNED_SHORT type is supported
  </code></pre>
  
  <p>It's working fine on IE11 on windows 7.</p>
  
  <p>Any help would be greatly appreciated.</p>