[horde] ingo vacation only

[Chris Flav]

Hello, 

I am looking for a way to disable custom filter editing in ingo to allow 
for vacation-use only.  I haven't found in the prefs.php a way to 
disable this.  I see there is blacklist/whitelist/spam but not just 
general rule. 

I have found code snippets like this one; 

if (!Ingo::hasPermission('allow_rules')) { 

how do I set ingo to only allow the editing and activation/deactivation 
of the vacation rule? 

Thanks, 

C. Flav