prefix standard drains with 'builtin' to discourage admins from deleting them via 'kato drain delete'.
prefix standard drains with 'builtin' to discourage admins from
deleting them via 'kato drain delete'.

* builtin_apptail is requried for `s logs` to work properly
* builtin_cloudevents for console cloudevents
* builtin_katohistory for `kato history`

hpcloud/logyard,ActiveState/logyard