cleanup classpath setup java classes loading

[colinsurprenant]

this is a bit all over the place and there is code duplication for stuff like

module Backtype
  java_import 'backtype.storm.Config'
end

I think the classpath setup, java classes & jars loading should be handled in the environment setup using $CLASSPATH instead of passing the -cp arg in the Application class.

this would simplify setting up the environment for topology testing like in the redstorm-starter project.