/**
* Reads volume ids from given list in file,
* gets the aggregate zip files for the volumes,
* and writes them in a HathiTrust-style pairtree structure
* for compatibility with related systems.
*
* Designed specifically to work with the client for HathiTrust's Data API
* at https://github.com/mfall3/htdapiclient-getvol
*
* Usage is: java -jar volgetter.jar volumeListFile destinationRoot serviceEndpoint
*
* @param args
* arg[0] -> volumeListFile - the file containing a list of volume ids, one on each line
* arg[1] -> destinationRoot - the target root directory, must exist or be valid to create
* arg[2] -> serviceEndpoint - the url for the api client service
*/