Add Definitions to the Database Along with the Terms

[odakaui]

I would like to add a table to the database for the definitions of each term.

Pros:

• Allow the user to get the definitions for a term without querying a second database.
• Speed up listing terms with their definitions.
• Allow the user to sync existing definitions for a given term to Anki.
• Allow the user to store definitions from multiple dictionaries for a single term.
• Allow the user to use multiple dictionaries. (#30)

Cons:

• Require changes to the database, specifically the join table.
• Increase the amount of time required during an import operation.
• Require changes to the way dictionaries are queried.