[SPARK-5335] Fix deletion of security groups within a VPC

Please see https://issues.apache.org/jira/browse/SPARK-5335.

The fix itself is in e58a8b01a8bedcbfbbc6d04b1c1489255865cf87 commit. Two earlier commits are fixes of another VPC related bug waiting to be merged. I should have created former bug fix in own branch then this fix would not have former fixes. :(

This code is released under the project's license.

Author: Vladimir Grigor <vladimir@kiosked.com>
Author: Vladimir Grigor <vladimir@voukka.com>

Closes #4122 from voukka/SPARK-5335_delete_sg_vpc and squashes the following commits:

090dca9 [Vladimir Grigor] fixes as per review: removed printing of group_id and added comment
730ec05 [Vladimir Grigor] fix for SPARK-5335: Destroying cluster in VPC with "--delete-groups" fails to remove security groups