Relocalization note/future FIXME (per chrisdo, 20110315):  At moment,
full localization info is in AppSubmissionContext passed from client to
RM and then to NM for AM-container launch:  no difference between AM-
localization and MapTask- or ReduceTask-localization, so can assume all
OK.  Longer-term, will need to override uber-AM container-localization
request (\"needed resources\") with union of regular-AM-resources + task-
resources (and, if maps and reduces ever differ, then union of all three
types), OR will need localizer service/API that uber-AM can request
after running (e.g., \"localizeForTask()\" or \"localizeForMapTask()\").