do not close NULL database connections on startup
bailout in case of TRACE_EMERG again, and log TabortHandler at TRACE_EMERG
de/re-code subject in native auto-reply
add explicit check for pthread support in glib
POP3: audit message retrieval and align with imap code
Use proper id in oracle blob comparison prep statement
Cleanup orphaned headername and headervalue records

Improve -t (test for message integrity) switch, seek for and remove orphaned
headername and headervalue records.
Mantis: http://www.dbmail.org/mantis/view.php?id=1008
UTIL: fix counters
fix small leak
Properly unescape multiple backslash sequences
Increase max username length according to db schema

Mantis: http://www.dbmail.org/mantis/view.php?id=991
handle potential overflow
bump and tag 3.1.7
Merge tag 'v3.1.7' into autotools