title: CharacterSet containing all variation of letters
body: <p>I'm working on a registration form where the user has to enter their full name, meaning that the only <strong>acceptable characters for this specific textfield should be (A-Z, a-z)</strong> plus " " (space) but no numbers, nor special caracter such -`+¨¨_{ etc. It should also <strong>accept accents</strong>, such as: [à, é, û] and all other combinations for all letters.</p>
  
  <p>What I have right now is:</p>
  
  <pre><code>- (BOOL)textField:(UITextField *)field shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString *)characters {
  
      NSMutableCharacterSet *mySet = [NSMutableCharacterSet characterSetWithCharactersInString:@"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZñ. "];
  
      return ([characters rangeOfCharacterFromSet:[mySet invertedSet]].location == NSNotFound);
  }
  </code></pre>
  
  <p>Which works fine but doesn't include the accented characters that I need to support, and I'm sure there should be simpler way of including the missing characters without having to type them one at a time. </p>