fails:Regexp#to_s displays options if included
fails:Regexp#to_s shows non-included options after a - sign
fails:Regexp#to_s shows all options as excluded if none are selected
fails:Regexp#to_s shows the pattern after the options
fails:Regexp#to_s displays groups with options
fails:Regexp#to_s displays single group with same options as main regex as the main regex
fails:Regexp#to_s deals properly with uncaptured groups
fails:Regexp#to_s deals properly with the two types of lookahead groups
fails:Regexp#to_s returns a string in (?xxx:yyy) notation
fails:Regexp#to_s handles abusive option groups
