Add recipe for setting umask (#1038)

* Add recipe for setting umask

Closes #1032

* Add explicit reference to Java Server archetype

Author: keirlawson

src/sphinx/recipes/umask.rst

@@ -0,0 +1,20 @@
+.. _umask:
+
+Setting the umask for your process
+==================================
+
+When using the :ref:`java-server-plugin`, the umask, associated with the user running the process, 
+will determine what permissions files generated by the process, such as log file, will have.  Usually the system default umask
+for daemons is fine and can be left unchanged, however sometime the need arises to oerride it.
+
+System V/systemd
+----------------
+
+To set a custom umask for your application that is running either via a System V init script or systemd, the umask can be 
+specified via a custom ``/etc/default/appname`` file.  The contents of this file can be specified by creating a template at 
+``src/templates/etc-default`` and adding a line such as the following:
+
+
+.. code-block:: bash
+
+    umask 022