* add end ports to cloudstack portforwarding\n* fix list port forwarding rules for node\* optimize cloudstack ex_list_port_forwarding_rules method
* add to EC2 driver several new methods\n* list_images\n* list_volumes\n* ex_create_snapshot ex_delete_snapshost ex_delete_image ex_delete_keypair ex_modify_image_attribute
* add test for delete/list snapshots
* finish tests for new features in ec2 driver
* add fixtures for tests