Pylint doesn't like our cinder.objects namespace that is populated
dynamically and shows numerous errors for non-existing members of that
namespace. To fight this we've added multiple pylint exceptions like
"Module 'cinder.objects' has no 'Backup' member". New additions were
needed in case of new objects introduction or first usages of them.
This commit switches these exceptions to a regexp to make sure no new
additions will be needed in the future. Furthermore it moves some
non-object related messages into a general exception list.
Change-Id: I6252d3447f8793d4acd666265a59887e637ce614