Add monitoring_log_requests

Addons that logs requests for usage analysis

monitoring_log_requests/README.rst

@@ -0,0 +1,17 @@
+.. image:: https://img.shields.io/badge/licence-AGPL--3-blue.svg
+    :alt: License
+
+Monitoring: Requests Logging
+============================
+
+This addon is used to output in the logs informations about the user's
+requests.  Data such as *what* is the request, *who* requested it and *how
+much* time did it took to complete could then be extracted from the logs and
+loaded in an analysis tool such as ElasticSearch/Kibana.
+
+Each log line is a JSON with the monitored fields, so it is easier to parse.
+
+The logs are prefixed with ``monitoring.http.requests`` so be sure to enable
+this path in the log handler::
+
+    - LOG_HANDLER=":WARNING,monitoring.http.requests:INFO"