add DragonFlyBSD support to modules/system/{user,group}

lib/ansible/modules/system/group.py

@@ -248,6 +248,15 @@ class FreeBsdGroup(Group):
         return (None, '', '')
 
 
+class DragonFlyBsdGroup(FreeBsdGroup):
+    """
+    This is a DragonFlyBSD Group manipulation class.
+    It inherits all behaviors from FreeBsdGroup class.
+    """
+
+    platform = 'DragonFly'
+
+
 # ===========================================
 
 class DarwinGroup(Group):

lib/ansible/modules/system/user.py

@@ -119,7 +119,8 @@ options:
         default: "no"
     login_class:
         description:
-            - Optionally sets the user's login class for FreeBSD, OpenBSD and NetBSD systems.
+            - Optionally sets the user's login class for FreeBSD, DragonFlyBSD, OpenBSD and
+              NetBSD systems.
     remove:
         description:
             - When used with C(state=absent), behavior is as with C(userdel --remove).
@@ -170,7 +171,7 @@ options:
     expires:
         description:
             - An expiry time for the user in epoch, it will be ignored on platforms that do not support this.
-              Currently supported on Linux and FreeBSD.
+              Currently supported on Linux, FreeBSD, and DragonFlyBSD.
         version_added: "1.9"
     local:
         description:
@@ -929,6 +930,17 @@ class FreeBsdUser(User):
         return (rc, out, err)
 
 
+class DragonFlyBsdUser(FreeBsdUser):
+    """
+    This is a DragonFlyBSD User manipulation class - it inherits the
+    FreeBsdUser class behaviors, such as using the pw command to
+    manipulate the user database, followed by the chpass command
+    to change the password.
+    """
+
+    platform = 'DragonFly'
+
+
 class OpenBSDUser(User):
     """
     This is a OpenBSD User manipulation class.