libmateweather: Upgraded to 1.6.1

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackware-id.org>
mate-applets: Upgraded to 1.6.1
Bumped minimum version of libmateweather to 1.6.1
Update TREE.TXT

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackware-id.org>