Refactor

Moved code around so that it matches the default implementation of the assets pipeline.
i.e. Created a LessProcessor and set that against the AssetFile

This is useful as other processors can be inserted to act before less
compilation.

I am working on a GSP preprocessor to allow config etc to be injected into assets. It works by adding a processor first in the chain.

I have used this version successfully but please do conduct your own tests and feedback.