Navigation fixtures no longer take args

- This allows for reusing an open browser in the legacy tests
- They also work the same in and out of py.test.
- Fortunately, there wasn't a lot of nav fixtures being called as functions,
  so it was a tiny refactor
- Also removed the NAvigatoinFixture class, as it was only doing functional work
add wait for visible select
flake cleanup
Fix Radio object
check evminit and more rpms
Merge pull request #288 from dajohnso/fix_tagging_tests

Fix tagging tests
Merge pull request #293 from seandst/add-provider-fixes

Navigation fixtures no longer take args
Working RBAC tests!

- added waits to the related page models
- broke group, role, and user tests out of a monolithic class,
  and organized them into their own files
lint
Merge pull request #292 from dajohnso/add_appliance_tests

check evminit and more rpms
Merge pull request #291 from psav/fix_radio

Fix Radio object
use get_element
Merge pull request #294 from seandst/rbac-waits

Working RBAC tests!
Better YAML overriding

Now it does not take just the root element into the account, but it crawls throught the dictionary and only updates the values that are present in the new dictionary. It converts all dicts to Configs, other values than specified in override dict are not touched.
My counterproposal...
Merge pull request #295 from dajohnso/tweak_select_dropdown

use get_element in select_dropdown*

(I'm excited to discover what gets broken by this change due to ridiculousness.)
Updated ldap auth tests to cope with new nav fixture behavior
Added new Tree element
Re-vamp of Development Guide
infra_providers: Refresh

* Added possibility to refresh the query to speed things up
* Made the check for settings use the refresh if the data have not come yet