Run one volume deletion task at a time - EUCA-9500

EUCA-9500

Conflicts:
	clc/modules/block-storage/src/main/java/com/eucalyptus/blockstorage/BlockStorageController.java
EqualLogic SAN provider performance improvements - EUCA-9502

Reliability is improved by reading up to the SSH prompt on connect
rather than sleeping for a hard coded amount of time and by sending a
quit command prior to disconnecting.

Running a batch of commands on a single connection is now supported to
reduce per-command overhead and improve performance.

Timing information can now be logged to support diagnosing performance
issues.

EUCA-9502
EUCA-9503 added SC_REQUEST_TIMEOUT conf param