Per discussion in ML, update UnderFileSystemHdfs class to throw IOException as is instead of wrapping it as runtime.
This will follow the abstract method definitions that could throw IOException instead.
Revert accidental commit to return empty String array to back to null (will address it with differetn PR)
Merge pull request #304 from hsaputra/change_runtime_to_io_exception_underfshdfs

Update UnderFileSystemHdfs class to throw IOException instead of Throwables.propagate(te)