SLIDER-622 add a second destroy operation after a sleep, may handle directory-not-deleted problems
SLIDER-208 with too many zk dirs the scan for a test-classes in the (limited) stdout buffer fails
SLIDER-622 try and make TestStandaloneAgentAM more resilient to delayed-deletion
SLIDER-208 TestLongLivedProcess: with too many zk dirs the scan for a test-classes in the (limited) stdout buffer fails