Index option of autocomplete accepts uri

`index` option of “autocompleted” fields can be uri of any page to
complete with all of that page’s children
added IT language
removed duplicate language entries
Fix #20
Fix #202
important bugfix for panel forms
Fix #200
Merge pull request #203 from e0ae240/it_language

Added IT language
Fix #201
Merge pull request #176 from gBokiau/autocomplete-arbitrary-children

Index option of autocomplete accepts uri
updated polish translation
bug fix for broken file fields
ie bugfixing
Old IEs get a warning at login
first implementation of user roles
blocked the login for non-panel users
bugfixes for the installation
removed temporary readme