Allow letters and symbols inside the Google+ CPF

As i explained in this topic, Google Plus provides users to choose a custom username for themselves, other than the autogenerated id number. So, the CPF should allow letters, numbers and symbols into it.

Users that set themselves a custom username find it difficult to find their id after they got used with their name. The Id redirects to the custom profile url, so there are no issues with the current way it is now.