How to add an object type in the types we can add into an ogroup

This is intended to serve as an example of plugin modification. Here the point was to be able to add DSA accounts into object groups.

First, we had to know what was the object type, for this I looked into my plugin and saw that DSA entries were defined in class_simpleSecurityObject.inc with:

'plObjectType'  => ['simpleSecurityObject' => [

So I need to assign a letter to DSA entries object type in the ogroup class:

--- ./plugins/admin/groups/class_ogroup.inc    2016-09-26 11:42:38.284429999 +0000
+++ ./plugins/admin/groups/class_ogroup.inc    2016-09-26 10:45:30.012429999 +0000
@@ -147,6 +147,7 @@
     'T' => 'terminal',
     'F' => 'phone',
     'P' => 'printer',
+    'D' => 'simpleSecurityObject'
   ); 

Now I can add my DSA entries to groups!