Add support for capturing stdout associated with job events and ad hoc command events.

* New event types for stdout lines not associated with a callback event.
* New stdout, start_line, end_line and verbosity fields for job/ahc events.
* Callback plugins to wrap Ansible default/minimal stdout callbacks and embed callback event data using ANSI escape sequences.
* Callback plugin library to wrap ansible.display.Display class methods.
* Output filter to extract event data from stdout and create job/ahc events.
* Update stdout formats to strip new ANSI escape sequences.

awx/api/permissions.py

@@ -189,8 +189,6 @@ class TaskPermission(ModelAccessPermission):
         # token.
         if view.model == Inventory and request.method.lower() in ('head', 'get'):
             return bool(not obj or obj.pk == unified_job.inventory_id)
-        elif view.model in (JobEvent, AdHocCommandEvent) and request.method.lower() == 'post':
-            return bool(not obj or obj.pk == unified_job.pk)
         else:
             return False