add a custom DB backend that provides system-level SQL profiling

run this command on _any_ node in an awx cluster:

$ awx-manage profile_sql --threshold=2.0 --minutes=1

...and for 1 minute, the timing for _every_ SQL query in _every_ awx
Python process that uses the Django ORM will be measured

queries that run longer than (in this example) 2 seconds will be
written to a per-process sqlite database in /var/lib/awx/profile, and
the file will contain an EXPLAIN VERBOSE for the query and the full
Python stack that led to that SQL query's execution (this includes not
just WSGI requests, but background processes like the runworker and
dispatcher)

$ awx-manage profile_sql --threshold=0

...can be used to disable profiling again (if you don't want to wait for
the minute to expire)

awx/main/management/commands/profile_sql.py

@@ -0,0 +1,21 @@
+from django.core.management.base import BaseCommand
+
+from awx.main.tasks import profile_sql
+
+
+class Command(BaseCommand):
+    """
+    Enable or disable SQL Profiling across all Python processes.
+    SQL profile data will be recorded at /var/lib/awx/profile/
+    """
+
+    def add_arguments(self, parser):
+        parser.add_argument('--threshold', dest='threshold', type=float, default=2.0,
+                            help='The minimum query duration in seconds (default=2).  Use 0 to disable.')
+        parser.add_argument('--minutes', dest='minutes', type=float, default=5,
+                            help='How long to record for in minutes (default=5)')
+
+    def handle(self, **options):
+        profile_sql.delay(
+            threshold=options['threshold'], minutes=options['minutes']
+        )