check if year in the copyright notice in README needs an update.

mark "Fix commited" tickes as "resolved" in the bugtracker.

update localisations using
    xgettext -k_ -kN_ --from-code utf-8 -o ./po/mat-gui.pot mat-gui.py ./data/mat.glade

update changelog:
    git log -> CHANGELOG

update version number (Don't be affraid to use -rc or -beta)
    MAT/mat.py -> __version__ = $VERSION

commit release changes
    git commit CHANGELOG MAT/mat.py

create a tag
    git tag -s $VERSION

push the tag
    git push --tags

archive's creation :
    git archive --format=tar.xz --prefix=mat-$VERSION/ $VERSION > mat-$VERSION.tar.xz

signing:
    gpg --armor --detach-sign mat-$VERSION.tar.xz

upload:
    https://mat.boum.org/files

add changelog
    https://mat.boum.org/
