Update Changelog about commands logging mechanism

Add an entry to the Changelog about the 'Logging mechanism for Synnefo
management commands'.

Closes #3: Log all stdout/stderr for snf-manage invocations

Changelog

@@ -32,6 +32,15 @@ Synnefo-wide
   * All existing resources have been assigned to the respective
     user-specific base projects.
 
+* Logging mechanism for Synnefo management commands
+
+  * Log all stdout and stderr output of every invocation of snf-manage,
+    on unique filenames under a given directory.
+
+  * Add a new setting in the snf-common package, namely 'LOG_DIR', which
+    specifies the directory to be used by Synnefo components to write
+    their log files.
+
 Astakos
 -------
 

docs/admin-guide.rst

@@ -2335,6 +2335,12 @@ The logging configuration dictionary is defined in
 The administrator can have logging control by modifying the ``LOGGING_SETUP``
 dictionary, and defining subloggers with different handlers and log levels.
 
+By default snf-manage will log any command that is being executed along with
+its output under the directory ``LOG_DIR``/commands. The ``LOG_DIR`` directory
+can be changed from the ``00-snf-common-admins.conf`` configuration file and
+the whole snf-manage logging mechanism can be disabled by changing the
+``LOGGER_EXCLUDE_COMMANDS`` setting to ".\*".
+
 
 .. _scale-up: