setup*provider utils and fixtures all use new provider classes

This will break your automation if you don't have the AJAX patch installed:
`scripts/patch_ajax_wait.py <address of your appliance>`

Depends on #473, doesn't seem to ruin everything.

To get a good idea of what things look like now, build the docs, then look at these two files:
- `modules/fixtures/fixtures.mgmt_system.html`
- `modules/utils/utils.providers.html`

Apologies to folks that may have pulled setup_provider(s) from cfme.cloud/infra.provider; they're in utils/providers now.