Rename database proposition fields

Sygned-off-by: David Carlos <ddavidcarlos1392@gmail.com>
Rename some  DatabaseInterface class atributes.
Generate database file.

Sygned-off-by: David Carlos <ddavidcarlos1392@gmail.com>
Create User table.

Sygned-off-by: David Carlos <ddavidcarlos1392@gmail.com>