Comment 1 for bug 823887

so currently we have three types of builds split up in two categories:

 1. official tip/continuous
 2. official release
 3. user builds

not sure if we should start differentiate ACLs and retention of 1. and 2. by introducing another

I would think for 1. we want >30 days no matter how many builds; for 2. we want never delete and for 3. something reasonably short (like one week or at least 7 builds)