Features:
+* make eparis happy: in the getty generator open ttys to run gettys on
+ first with O_NDELAY and check isatty() to filter out invalid ttys.
+
* MessageQueueMessageSize= and RLimitFSIZE= (and suchlike) should use parse_iec_size().
* man: move .link, .network and .netdev documentation into their own