i18n-it: update many broken fuzzy messages
I started updating many fuzzy messages which no longer expressed the
intended meaning - new translations are inserted only to keep
coherence.
Not all fuzzy messages have been fixed, yet.
i18n-it: readd missing non-ASCII characters
Some accented vowels had disappeared.
i18n-it: avoid using two spaces after a '.'
See http://en.wikipedia.org/wiki/Sentence_spacing to verify that
single spacing is indeed correct.
test-check-code: fix test after
e1359ad582f6