EUCA-5834: make sure the configurable ELB subdomain is valid
EUCA-5820: Cannot deregister instances from loadbalancer
 - when the column, stateChangeStack, is filled, the query example class shuld have it set to Null
Merge branch 'dev/spark/EUCA-5834' into dev/spark/services
EUCA-5852: ELB: Metrics for RequestCount and HTTPCodes need to change the way they put metrics
 -- reimplemented cloudwatch metrics data format following the AWS way
EUCA-5841: HealthyHostCount and UnHealthyHostCount are now reported in every 1 minute