+TK/01 Bugzilla #401. Fix DK spooling code so that it can overwrite a
+ leftover -K file (the existence of which was triggered by #402).
+ While we were at it, introduced process PID as part of the -K
+ filename. This should rule out race conditions when creating
+ these files.
+
+TK/02 Bugzilla #402. Apply patch from Simon Arlott, speeding up DK signing
+ processing considerably. Previous code took too long for large mails,
+ triggering a timeout which in turn triggers #401.
+
+TK/03 Introduced HAVE_LINUX_SENDFILE to os.h-Linux. Currently only used
+ in the DK code in transports.c. sendfile() is not really portable,
+ hence the _LINUX specificness.