Bulk load/unload fixes

- changes to sqenvcom.sh to support native compressions
  for Clouder and Hortonworks distributions (tested on
  cluster)
- rework from provious checkin.
- fix for bug 1387202 which cause bulk unload to hang
  when target loaction is invalid.

Change-Id: Ia6046dfb2b5ff2f986b8306c26a991991a3da780