[WIP] Word level features

[lepisma]

This branch add words level confidence and timing back. Python package is also upgraded. There is a minor structure change where we need word_boundary.int file too. This can be made optional.

[lepisma]

TODO:

• [x] throw warning when word_boundary is not found in initialization. throw error in request
• [x] update doc and model structure guidelines

[lepisma]

not throwing error in request. just disabling.