Localization by IP and italian localization

Added localization system by IP and italian localization
Site difficulty in sites.json now is:
0 for easy
1 for medium
2 for hard
3 for impossible

Example:

{
"name": "9GAG",
"url": "https://9gag.com/member/delete",
"difficulty": "0",
"notes": "Login to your account, go to parameters, click Delete my
account. Confirm by clicking I want to delete my account. And again by
clicking Delete my 9GAG account.",
"notes_it": "Logga il tuo account, vai su parameters, clicca Delete my
account. Conferma cliccando I want to delete my account. E ancora
cliccando Delete my 9GAG account."
},

/inc/script.js no more needed i moved the script inside dev.php to echo
php localization

Parent
https://github.com/rmlewisuk/justdelete.me/pull/144
Revert "Localization by IP and italian localization"

This reverts commit 8a82ee240173278cb51865791ad38c6efdfd5c10.
Merge remote-tracking branch 'upstream/master'
Implement language switcher

Change language without refreshing page
New file: definitions.json

To add notes for a language add this line to site in sites.json
> "notes_it": "Logga il tuo account, vai su parameters, clicca Delete my
account. Conferma cliccando I want to delete my account. E ancora
cliccando Delete my 9GAG account."

If site note not exists in the language the user choose it shows EN note
It also saves a cookie containing the language choosed for future site
visits
Fixes and merge
Removed arrow css
GoSquared flags, updated gb to en, updated readme, licence and contributing