Modify ingest to support aux.xml files in HDFS

[djohnson729]

For tif files, metadata can be stored in aux.xml files stored alongside the .tif file. When the source file is on the local file system, it works fine, but GDAL is unable to read files from HDFS, so we need to have code in place that can read the .aux.xml files from HDFS ourselves.

This should be done in GDALUtils.open() because in there we know if we're trying to read from HDFS. And we can write the code to read the metadata and set it into the Dataset for the image.