allow smtpd to enable a route it has disabled
break early if possible
* make /incoming specific to queue_fs.c
* create incoming message in /temporary and pass the path to the commit
  backend function, which prototype has been modified.
* simplify queue_ram.c accordingly
* purge /temporary on startup
Merge branch 'master' of ssh.poolp.org:/git/opensmtpd
Merge branch 'master' of ssh://ssh.poolp.org/git/opensmtpd