CLOUDSTACK-874: Ability to delete Events and Alerts

This feature will provide the functionality to delete or archive
the Alerts/Events.
Delete or archive alerts APIs are available only for root-admin,
delete or archive events are available for regular users.
Add missing Apache license header.
CLOUDSTACK-1451 Pass randomly generated UUID instead of empty string when create internal account as a part of project creation. Otherwise entityexistsexception would happen when attempt to create more than 1 project in the system