cmogstored 1.4.3 - mostly non-GNU/Linux fixups

For all platforms, the startup device scanning thread at startup
may not handle EINTR properly.  This bug only manifested at
startup and does not affect running instances.  However, this
bug is also readily apparent on newer versions of FreeBSD
which support the ppoll function call.

Thanks to Mykola Golub <trociny@FreeBSD.org> for the bug report
which led to this release.

For systems lacking epoll_pwait (older GNU/Linux, all *BSDs),
there is also a bugfix for systems which experience signal spam
leading to errno clobbering in the main thread.  This bug was
only only noticed due to a bug report against Ruby:

	https://bugs.ruby-lang.org/issues/10866

There is no need to upgrade if 1.4.1 is already running well
on modern GNU/Linux systems capable of epoll_pwait.  But then
again nginx-style SIGUSR2 upgrades are transparent to clients.

shortlog since 1.4.2:

      Makefile.am: fix publish rule for website
      Fix assertion failure during startup
      avoid relying on ppoll as a cancellation point
      preserve errno when inside sig handler for self-pipe