test_auth_and_roles works with the new nav menu structure

* Also tweaked the menu locators a little bit so hopefully they're easier to use
auth and roles tests use testgen and are parametrized from cfme_data

- Due to the way pytest.skip works in collection (see note in utils.testgen),
  it made sense to break these up into separate modules so testgen could do
  its job easily.
- I *think* the old configure_auth_mode in fixtures has been completely replaced
  by cfme.fixtures.configure_auth_mode...
I'm not sure where reverse_lookup and visible_pages belong...

..but I'm sure that they belong together wherever that may be
DHTMLSelects take advantage of being locatable
Merge pull request #602 from seandst/nav-auth-fixup

Nav auth fixup
Merge pull request #611 from seandst/lazycache

lazycache method decorator!
This was breaking the docs :(
conf load errors downgraded to warnings

The lack of a config file can eventually trigger ImportError, which
(among other things) breaks our docs build. It's also really rude.
This is now a warning, which prints a nice error message without
breaking everything.
Merge pull request #614 from seandst/docs-fix

conf load errors downgraded to warnings
DB queries
Update configure navigation to work
Merge pull request #613 from mfalesni/some_db_queries

DB queries
Merge pull request #609 from seandst/select-loc-oops

DHTMLSelects take advantage of being locatable
Crappy workaround for #618
lazycache is easier to read, doesn't eat docstrings