Crafted a pathetic CommonJS require clone.

This is nice because now I can share server libraries with the client. No
dependencies on other libraries are checked and it uses 'eval' which is highly
deprecated. Still the syntax is the same as on the server side.
Used server-side lib/range to test if filter gets more restrictive.

I am not satisfied with this because it might imply that the filter change
function has to be updated as soon as more filters are added. There must be
better way.