OpenDNSSEC 1.3.13 - 2013-02-20

Bugfixes:
* OPENDNSSEC-388: Signer Engine: Internal serial should take into account
  the inbound serial.
* OPENDNSSEC-242: Signer Engine: Could get stuck on load signconf while
  signconf was not changed.
* Signer Engine: Fixed locking and notification on the drudge work queue,
  signals could be missed so that drudgers would stall when there was work to
  be done.

(pettai)