sample: java hello world. use resource. change bundled-file example.

We want to demonstrate resources. We want to demonstrate file-bundles. The 'hello world' example was using a bundled file for something you'd more-properly use a resource for. So don't do that.

Instead, load two "greetees". Load one from a bundled file, one from resource.

Testing Done:
$ ./build-support/bin/ci.sh

$ ./pants goal bundle src/java/com/pants/examples/hello/main
$ cd dist/main-bundle/
$ java -jar main-bin.jar

$ ./pants goal run src/scala/com/pants/example/hello/exe

Bugs closed: https://github.com/pantsbuild/pants/issues/110

Reviewed at https://rbcommons.com/s/twitter/r/350/