Locale code: it-IT

Thanks to our collaborators (listed according the version in which they made their collaboration):

• [[https://www.transifex.com/accounts/profile/walterix/ walterix]] (Walter Torri)
  • b2evolution 5.2.x
  • b2evolution 5.0.x
  • b2evolution 4.x
• b2evolution 1.8.x: _TeRmInEt_
• b2evolution 0.9.x: Antonio Fragola & Matteo Lenardon