Respect/Validation — pull request #111 by ramaciotti (2013-01-22 23:22:37+00:00)
Title: More Ctype rules changes

I've just finished renaming the classes, making Xdigit inherit from AbstractCtypeRule and updating the documentation (except for `printing` that I'm waiting for we to decide a name).

Keep in mind that Print isn't working because of how PHP handles the Print keyword.