release v0.22.2

The bug https://bugzilla.samba.org/show_bug.cgi?id=11413 makes MPD
crash after at most a minute of using the plugin.  Since this bug is
five years old already and it doesn't look like it will ever be fixed,
all libsmbclient code in MPD is scheduled for removal.  For now, the
plugin is disabled by default so people are less likely to hit the
crash bug.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/991

Closes https://github.com/MusicPlayerDaemon/MPD/issues/981

Reduces header dependencies.

This got lost in commit 5d597a36 (v0.21.19), but it was never
noticed because the state_file_interval was way too short due to
commit 3413d1bf, fixed recently by commit 27cc7b35

Fixes use-after-free bugs causing assertion failures at shutdown,
because all "abandoned" SocketEvents are still in the linked list.

Closes https://github.com/MusicPlayerDaemon/MPD/issues/986
Closes https://github.com/MusicPlayerDaemon/MPD/issues/987

dup2 returns new_fd on success, not 0

Reduce header dependencies for SocketEvent.hxx.

Not only those which are "ready".

Prepare for adding more code here.

This implements proper rounding, amending commit dcbb9fe0

release v0.22.1

snprintf() is available on mingw, and the libnfs kludge broke the
build with mingw, because sprintf_s() was now both an inline function
and a "dllimport" function (because the macro renamed the inline
function snprintf() to sprintf_s() in mingw's stdio.h).

Fixes regression from commit 1473d847