7.8.3 Message selection

`--translated'

Keep translated messages, remove untranslated messages.

`--untranslated'

Keep untranslated messages, remove translated messages.

`--no-fuzzy'

Remove `fuzzy' marked messages.

`--only-fuzzy'

Keep `fuzzy' marked messages, remove all other messsages.

`--no-obsolete'

Remove obsolete #~ messages.

`--only-obsolete'

Keep obsolete #~ messages, remove all other messages.