ref-manual: Added extrausers class and EXTRA_USERS_PARAMS variable.

(From yocto-docs rev: 9638963d1eb7c4cf6d724b3633ac6410b13f6b2d)

Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

documentation/ref-manual/ref-variables.xml

@@ -1788,6 +1788,40 @@
             </glossdef>
         </glossentry>
 
+        <glossentry id='var-EXTRA_USERS_PARAMS'><glossterm>EXTRA_USERS_PARAMS</glossterm>
+            <glossdef>
+                <para>
+                    When a recipe inherits the
+                    <link linkend='ref-classes-extrausers'><filename>extrausers</filename></link>
+                    class, this variable provides image level user and group
+                    operations.
+                    This is a more global method of providing user and group
+                    configuration as compared to using the
+                    <link linkend='ref-classes-useradd'><filename>useradd</filename></link>
+                    class, which ties user and group configurations to a
+                    specific recipe.
+                </para>
+
+                <para>
+                    The set list of commands you can configure using the
+                    <filename>EXTRA_USERS_PARAMS</filename> is shown in the
+                    <filename>extrausers</filename> class.
+                    These commands map to the normal Unix commands of the same
+                    names:
+                    <literallayout class='monospaced'>
+     # EXTRA_USERS_PARAMS = "\
+     # useradd -p '' tester; \
+     # groupadd developers; \
+     # userdel nobody; \
+     # groupdel -g video; \
+     # groupmod -g 1020 developers; \
+     # usermod -s /bin/sh tester; \
+     # "
+                    </literallayout>
+                </para>
+            </glossdef>
+        </glossentry>
+
     </glossdiv>
 
     <glossdiv id='var-glossary-f'><title>F</title>