title: wro4j less-compiler compiles .css files, too
body: <p>I am using wro4j 1.7.3 with less4j/lessCSS-compiler. </p>
  
  <pre><code>preProcessors=less4j,
  yuiCssMin,googleClosureSimple
  </code></pre>
  
  <p>In my wro.xml, I have something like:</p>
  
  <pre><code>&lt;group name='css'&gt;
      &lt;css&gt;/resources/css/base.css&lt;/css&gt;
  &lt;/group&gt;
  </code></pre>
  
  <p>When compiling, I will get a error because wro4j treats my *.css-file also as a *.less-file. </p>
  
  <pre><code>Exception occured while processing: ro.isdc.wro.WroRuntimeException: 
  Could not compile    less. 1 error(s) occured:
  ERROR 437:1 missing EOF at '}' in stylesheet (which started at 23:1)
  , class: ro.isdc.wro.WroRuntimeException,caused by:     
  com.github.sommeri.less4j.Less4jException Could not compile less. 1 error(s) occured:
  ERROR 437:1 missing EOF at '}' in stylesheet (which started at 23:1)
  </code></pre>
  
  <p>When using lessCSS, instead of less4j, the error reason is better shown:</p>
  
  <pre><code>MEZ: [ERROR] Exception occured while processing: ro.isdc.wro.WroRuntimeException: Could  
  not execute the script because: 
  {
  "type": "Runtime",
  "message": "error evaluating function `saturate`: Cannot find function toHSL in object   
  [object Object].",
  "filename": null,
  "index": 11114.0,
  "line": 754.0,
  "callLine": null,
  "callExtract": null,
  "stack": null, 
  "column": 17.0,
  "extract": [
  ".img-saturate{ ",
  "   -webkit-filter: saturate(500%);",
  "   -moz-filter: saturate(500%);"
  ]
  }, class: ro.isdc.wro.WroRuntimeException,caused by:  Could not execute the script   
  because: 
  {
  "type": "Runtime",
  "message": "error evaluating function `saturate`: Cannot find function toHSL in   
  object [object Object].",
  "filename": null,
  "index": 11114.0,
  "line": 754.0,
  "callLine": null,
  "callExtract": null,
  "stack": null,
  "column": 17.0,
  "extract": [
  ".img-saturate{ ",
  "   -webkit-filter: saturate(500%);",
  "   -moz-filter: saturate(500%);"
  ] 
  }
  </code></pre>
  
  <p>Changing the processor-order does not help:</p>
  
  <pre><code>preProcessors=yuiCssMin,googleClosureSimple
  postProcessors=less4j
  </code></pre>
  
  <p>The error still exists.</p>
  
  <p>Is there a possibility, to say wro4j, that it should not treat files endings with css as less.</p>