Add SettingsWindow, make TrackerContext class public.
Enable Settings button, add click event handler.
Build SettingsWindow.
Add handlers to SettingsWindow buttons.
Add Setting model and migration.
Add method and properties to handle settings stored in database.
Reload settings from database after clicking Save in SettingsWindow.
Code properly storing settings.
Display error message if settings textbox values are wrong.
Merge branch 'feature/settings' into develop