improve readability of the honcho console logs in the dev environment

* colorize uwsgi and celery logs; DEBUG lines are green, WARN lines
  are yellow, ERROR lines (and tracebacks) are red
* pretty-print fact callback receiver JSON
* simplify the uwsgi log format so it's more legible

awx/settings/defaults.py

@@ -917,9 +917,9 @@ LOGGING = {
     },
     'handlers': {
         'console': {
+            '()': 'logging.StreamHandler',
             'level': 'DEBUG',
             'filters': ['require_debug_true_or_test'],
-            'class': 'logging.StreamHandler',
             'formatter': 'simple',
         },
         'null': {
@@ -1091,3 +1091,4 @@ LOGGING = {
         },
     }
 }
+COLOR_LOGS = False