Create ApplicationController::Filter#process_datetime_selector

Code deduplication (DRY)
Create ApplicationController::Filter#process_datetime_selector

Simplified character extraction from a string.
Create ApplicationController::Filter#process_datetime_selector

Explicitly declare this new method as private.
Create ApplicationController::Filter#process_datetime_selector

Simplified boolean logic around time_suffix computation.
Create ApplicationController::Filter#process_datetime_selector

Use new variable exp in place of @edit[@expkey]
Create ApplicationController::Filter#process_datetime_selector

Computed exp_value_key and defaulted exp_key to nil.
Create ApplicationController::Filter#process_datetime_selector

Compute value_key, instead of passing it as parameter.
Simplified ApplicationController::Filter#process_datetime_selector method
Expand render_flash with flash text.
Split and cleanup a bit ApplicationController::group_create_update.
Simplify ApplicationController::selected_consecutive?.
Remove the html tags <br/> that show up in the emailed report.

https://bugzilla.redhat.com/show_bug.cgi?id=1124936
Nullify the cluster_id on hosts when deleted

When Clusters are deleted, the ems_cluster_id should be nullified on residual
hosts.

As a performance concern, hosts are not automatically deleted when an
infrastructure provider is deleted.  However, the clusters may be.  In such
cases, the old ems_cluster_id will remain on the host record.

Then, if the same infrastructure provider is added back, and an ems_refresh is
initiated, the hosts attempt to resolve the ems_cluster_id (which points to
nothing now) and ends up with an object not found error from active record.

https://bugzilla.redhat.com/show_bug.cgi?id=1087476
Options/rbac minor code cleanup.
Split and cleanup ApplicationController#load_edit.
Refactor ApplicationController#flash_errors?.
Cleanup ApplicationController#load_edit calls.
Split method application_controller#get_view.
Create some tests for OpsController::rbac_user_edit.
remove some REXML monkey patches

We don't directly use REXML::XPath, so it doesn't make sense to test that
against nokogiri.