Transcription Annotations class with validator, tests, and constructor

[leandrumartin]

Might it be a good idea to rename this as a "Gloss" class for consistency with terminology? Or would that be more relevant as a separate class?

If I am correct in understanding that this is essentially a Gloss object, we should define what such an object would look like, with it including:

• All information that should be displayed to users browsing glosses
• Any information that should be searchable--currently, the public site's sidebar lists searching by tag, book, and theme

EDIT: I see now that there already is a Gloss interface in the project. Renaming might not be a good idea then.