Implemented test_cloud_instance_discovery.py

1. Added cfme/test/cloud/test_cloud_instance_discovery.py, which is based on cfme/tests/infrastructure/test_vm_discovery.py

2. Added _load_details() to the Provider class in cfme/cloud/provider.py

3. Added a try/catch around call to is_vm_suspended() in Vm.delete_from_provider() for cases where the provider doesn't support returning Vm status (EC2)

4. Paginator.find() now raises an error if the element is not found

5. Misc. small bug fixes and improvements
I copied/modified this from cfme/tests/infrastructure/test_vm_power_control.py, which has pytest.skip() as well, but I can change this to error out if you prefer. Also, this should print the error out when it happens, so I believe you should be able to see the error and kill the test before it runs all the way through.