Add fail_on_user option

fail_on_user option can be used to ignore silently
if the user cannot be removed because of remaining
privilege dependencies to other objects in the 
database. By default it will fail, so that this new 
behavior won't surprise unsuspecting users.

library/postgresql_user

@@ -194,13 +194,13 @@ def main():
             state=dict(default="present", choices=["absent", "present"]),
             priv=dict(default=None),
             db=dict(default=''),
-            fail_on_user=dict(default=True)
+            fail_on_user=dict(default='yes')
         )
     )
     user = module.params["user"]
     password = module.params["password"]
     state = module.params["state"]
-    fail_on_user = module.params["fail_on_user"]
+    fail_on_user = module.params["fail_on_user"] == 'yes'
     db = module.params["db"]
     if db == '' and module.params["priv"] is not None:
         module.fail_json(msg="privileges require a database to be specified")
@@ -221,12 +221,14 @@ def main():
     kw = dict( (params_map[k], v) for (k, v) in module.params.iteritems() 
               if k in params_map and v != "" )
     try:
-        db_connection = psycopg2.connect(database=db, **kw)
+        db_connection = psycopg2.connect(**kw)
         cursor = db_connection.cursor()
     except Exception, e:
         module.fail_json(msg="unable to connect to database: %s" % e)
     
+    kw = dict(user=user)
     changed = False
+    user_removed = False
     if state == "present":
         if user_exists(cursor, user):
             changed = user_chpass(cursor, user, password)
@@ -241,14 +243,16 @@ def main():
             changed = revoke_privileges(cursor, user, privs)
             user_removed = user_delete(cursor, user)
             changed = changed or user_removed
-
-    if fail_on_user and not user_removed:
-        msg = "unabel to remove user"
-        module.fail_json(msg=msg)
+            if fail_on_user and not user_removed:
+                msg = "unabel to remove user"
+                module.fail_json(msg=msg)
+            kw['user_removed'] = user_removed
 
     if changed:
         db_connection.commit()
-    module.exit_json(changed=changed, user=user, user_removed=user_removed)
+
+    kw['changed'] = changed
+    module.exit_json(**kw)
 
 # this is magic, see lib/ansible/module_common.py
 #<<INCLUDE_ANSIBLE_MODULE_COMMON>>