add toAscii method to Italian Internet provider

This was inspired by issue #189. Copied and adapted from French Internet provider. Even if current Person provider for Italian does not contains any accented letters, I added them anyway, for forward compatibility. The only current issue with Italian Person provider are names with accent inside, that currently are translated into invalid email, like "ld'amico@yahoo.com"
Update Internet.php
Update Internet.php
Merge pull request #206 from garak/patch-1

add toAscii method to Italian Internet provider