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 removed the try/catch and pytest.skip(), so now the error is output to the log. The failing test will have an 'error' result, and it will continue on to the next test (which is the behavior defined by pytest). This way you see the error message when it happens, but I'm not sure you see a full traceback, just the line that caused the exception