Modify access levels to allow more flexible subclassing

[attheodo]

Problem description

WSTagsFields API for the most part is open to modifications by exposing most of it's methods as public. However for better leveraging the core functionality of the library, and especially providing custom tokenization by overriding tokenizeTextFieldText(), the textField property needs to be made public. Consequently the BackSpaceDetectingTextField() needs to be accessible outside of the module.

Preferred solution

Make the above properties and class public.

[ricardopereira]

The WSTagsField.textField has been exposed for public access in v5.3. Thanks for the issue.

[attheodo]

Thank you for the effort man.