Add support for the @import command in css files

In a lot of my projects I work with skin modules for skinning. These consist of a css-file as "main" class. In order to correctly support all of the mx and spark components, I have to manually add the definitions of the default.css files of mx.swc and spark.swc into the main css file. I would like to be able to place these defintions in separate files "mx-default.css", "spark-default.css" and then simply import these in my main.css. This would clean up things quite a lot.