added ACP option to enable private groups

src/views/admin/partials/menu.tpl

@@ -23,6 +23,7 @@
 						<li><a href="{relative_path}/admin/settings/reputation">Reputation</a></li>
 						<li><a href="{relative_path}/admin/settings/email">Email</a></li>
 						<li><a href="{relative_path}/admin/settings/user">User</a></li>
+						<li><a href="{relative_path}/admin/settings/group">Group</a></li>
 						<li><a href="{relative_path}/admin/settings/guest">Guest</a></li>
 						<li><a href="{relative_path}/admin/settings/post">Post</a></li>
 						<li><a href="{relative_path}/admin/settings/pagination">Pagination</a></li>

src/views/admin/settings/group.tpl

@@ -0,0 +1,22 @@
+<!-- IMPORT admin/settings/header.tpl -->
+
+<div class="panel panel-default">
+	<div class="panel-heading">General</div>
+	<div class="panel-body">
+		<form role="form">
+			<div class="checkbox">
+				<label>
+					<input type="checkbox" data-field="allowPrivateGroups" checked> <strong>Private Groups</strong>
+					<p class="help-block">
+						If enabled, joining of groups requires the approval of the group owner <em>(Default: enabled)</em>
+					</p>
+					<p class="help-block">
+						<strong>Beware!</strong> If this option is disabled and you have private groups, they automatically become public.
+					</p>
+				</label>
+			</div>
+		</form>
+	</div>
+</div>
+
+<!-- IMPORT admin/settings/footer.tpl -->