cryptnet: If the caller specifies the location of a CRL, check a cert's revocation status against it.

Trying to unlock a volume that isn't locked is questionable behaviour on the
side of the application, but not an internal error.

This is allowed behaviour.

server: Don't set the idle event when a queue is destroyed, instead return success in WaitForInputIdle on process exit.

The issue was detected with Valgrind.