Make safeEmail really safe

Hi,

cf. #124 for the corresponding bug.

I removed `$safeEmailTld` from all localizations as it is obsolete now. Additionally I made `safeEmail()` and `safeEmailDomain()` final, as there are no other possible safe emails than the ones generated by the methods. If you don't agree with this change feel free to comment and I'll remove the final keyword.

When I started writing an appropriate unit test I noticed some problems with cross dependencies: The Internet-Provider does not work without Company, which in case does not work without Person. You don't get a nice error message though (only something like: "missing formatter"). Should I create another issue for this, or is this intended? You could for example check whether the needed providers are available in the generator in `__construct()` and break / add them if they are not. Thats why I did not include a unit test for my bugfix.

regards