Merge pull requst #107 ramaciotti
Removed duplicated rule Xdigits (there is Hexa already)
Removal of braces on single-line statements

I've only removed braces from the files I'd changed/created on my
last pull request.  Notice, however, that there are other files
where this still happens.
Removal of $acceptEmptyString

Notice that this changes the behaviour of some rules (of Digits in
special).  That's why some lines from the tests appear in the diff,
they were removed from the invalid data provider and where put into
the valid data provider.
Updated documentation

I've also marked hexa as deprecated and moved `countryInfo` to
its alphabetical position.