View: Implemented Classify method

Resolves #135. It's not complete yet needs some cleaning and documentation. I think the `gen_python_api` file should change for exporting variables like `CLASS_WORD_START` and etc.
Isn't this regexp based on the "[word_separators](http://docs.sublimetext.info/en/latest/reference/settings.html?highlight=word_separators#automatic-behavior)" setting? Let's use ```s, _ := v.Settings().Get("word_separators", "[!\"#$%&'()*+,\\-./:;<=>?@\\[\\\\\\]^_\`{|}~]").(string)``` or similar