Bump version to 4.10.9; Update ChangeLog.
Merge remote-tracking branch 'origin/collectd-4.10' into collectd-5.1

Conflicts:
	ChangeLog
	version-gen.sh
Bump version to 5.1.3; Update ChangeLog.
Merge branch 'collectd-5.1' into collectd-5.2

Conflicts:
	ChangeLog
	version-gen.sh
Bump version to 5.2.2; Update ChangeLog.
Merge branch 'collectd-5.2'
Bump version to 5.3.0; Update ChangeLog.
configure.in: Fix libgcrypt flags on FreeBSD.

On FreeBSD, AM_PATH_LIBGCRYPT sets LIBGCRYPT_CFLAGS but not
LIBGCRYPT_CPPFLAGS. Use both variables to be on the save side.