Italian Translation + improvements

I realized that the translations in Italian were not correct. so I began to translate and to make some code improvements: strings without translations, missing translations of form fields select / option.
Complete Italian Translation of User, Admin Modules
Partial Translation: Feed, Dashboard (missing menu) , Vis (missing multigraph javascript strings) Modules
To Do: My Electric, Node, Input Modules

Other improvements
-User Module - Language selector
![user-lang-selector](https://cloud.githubusercontent.com/assets/6896873/5309403/d303f076-7c23-11e4-8fd2-06720cd39e87.jpg)

-Vis Module - Object name and options translations
![vis-object name and option](https://cloud.githubusercontent.com/assets/6896873/5309434/63d04c12-7c24-11e4-8975-1eb41cc481e6.jpg)

-Vis Module - Multigraph Name
![vis-multigraph name](https://cloud.githubusercontent.com/assets/6896873/5309465/ece4f318-7c24-11e4-9790-9f5772872369.jpg)

- Dasboard - I realize a script for build the dashboard_langjs.php file. the script (/script/dashboard_langjs_builder.php) extract the "_Tr" string from javascript files then manually copy and paste in dashboard_langjs.php

- Other
of course we would rebuild the file ".po" and re-translate all other languages ...