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
Merge remote-tracking branch 'upstream/pr/1041' into HEAD

Conflicts:
	cfme/infrastructure/virtual_machines.py
cleanup/dedup code
Merge pull request #1041 and cleanup