Fixes for timelines and is_displayed()

* Timelines provider_init was not being set up before test_vm was
  attempting to refresh relationships. Made provider_init fixture a
  prerequisite for test_vm instead.
* is_displayed required a title to be set for a Region, but sometimes
  titles are not set as the Region is multipage, as title is not a
  required keyword, at the moment we jsut accept that if title is None,
  then the title matches.
Merge pull request #918 from psav/fix_timelines

Fixes for timelines and is_displayed()
flake8 all the things
Merge pull request #919 from jkrocil/flake8-all-the-things

Flake8
Fixed force_navigate to try ALL THE TIMES

* force_navigate was designed to try 3 times max.
* At some point in the distant past the _tries count was modified to >=2
  which forbid it from trying that elusive 3rd time.
* When a browser had an edit page open, and force_navigate tried to move
  it would....
 * Close the alert on try 1
 * Realise that there was an alert on try 2
 * Roll over and die as _tries >= 2
* Changing >= to > means that....
 * Close the alert on try 1
 * Realise there was an alert on try 2
 * Navigate to the right page on try 3
Merge pull request #921 from psav/fix_force_nav

Fixed force_navigate to try ALL THE TIMES
fix power control failures
Merge pull request #922 from dajohnso/fix-power-control

fix power control failures
Fix mgmt_system for VMware

* CFME does not import inaccessible VMs so not neither do we.
Merge pull request #923 from psav/fix_mgmt_utils

Fix mgmt_system for VMware