Change access of methods and vars in Tokenizer from 'private' to 'protected'

[waltyou]

Hi takayahilton,

Very appreciate your work on this repo. It help me a lot.

When I use it in my project, I found the access of methods and vars in Tokenizer.scala almost all are "private" so that i can't override some functions for my special requirement. Do you think if it is better to change them to "protected" ?