cssImport should support less import-once

[bbergstrom]

http://lesscss.org/#-importing

Using these currently blows up with a Rhino error:

25-Feb-2013 13:21:22    78019 ERROR RhinoScriptBuilder   - JavaScriptException occured: Could not execute the script because: 
25-Feb-2013 13:21:22    {
25-Feb-2013 13:21:22      "type": "Parse",
25-Feb-2013 13:21:22      "message": "Syntax Error on line 6600",
25-Feb-2013 13:21:22      "index": 154928.0,
25-Feb-2013 13:21:22      "filename": null,
25-Feb-2013 13:21:22      "line": 6600.0,
25-Feb-2013 13:21:22      "column": 0.0,
25-Feb-2013 13:21:22      "extract": [
25-Feb-2013 13:21:22        "/* Using  */",
25-Feb-2013 13:21:22        "../../../lib/bootstrap/less/variables.less\";",
25-Feb-2013 13:21:22        "../../../lib/bootstrap/less/mixins.less\";"
25-Feb-2013 13:21:22      ]
25-Feb-2013 13:21:22    }

It would be great if the CssImportPreProcessor supported import-once in addition to import for better support for LessCSS features.

[bbergstrom]

Also, if Less file is brought in via group-ref in the model, the cssImport processor should be smart enough to not import a duplicate.

[alexo]

please open a separate issue for your last request