Initial impl

This InputFormat allows decoupling the format of the data from the actual jobs. It implement isolation from classloader and configuration perspective.
It is intended as a better MultiInputFormat which allows reading a single input from multiple locations with different inputformats coming from separate isolated class loaders (child first class loading delegation) and configurations.

I think the hadoop API provides a util for copying a file from hdfs to local that might be a little nicer to work with