Extract method #update.
Remove Common include; provided by Repository.
Remove namespacing.
Add #focus! method to interface API.
Update with missing API methods.
Fix cursor visibility.
Add aliases for #next_item and #prev_item.
Add 'focus' example app to demonstrate interface focus and cursor visibility.
Update documentation; cursor has no effect in views.
Merge pull request #104 from gavinlaking/twerks

Add focus! to interface API, fix cursor visibility.