lei: ensure we run DESTROY|END at daemon exit w/ kqueue

lei: ensure we run DESTROY|END at daemon exit w/ kqueue

The fundamental difference which I originally missed when
implementing kqueue EVFILT_SIGNAL support is that it does not
consume signals like signalfd(2) does.  In other words, with
EVFILT_SIGNAL, it's possible for a single signal to be delivered
twice if we unblock signals upon leaving the event loop as we do
in lei.

Note: Our DS->event_loop and Sigfd APIs can/should probably be
changed to better accomodate EVFILT_SIGNAL differences from
signalfd without sacrificing usability of either.

This fixes the problem of leftover lei-ovv.dst*, lei_cfg-* and
skv.* files in $TMPDIR at the end of test suite runs on *BSD
when IO::KQueue is installed.