Core update and support

• Keyboard navigation. ← ↑ → ↓
• Automatic animation with custom time.
• New test, including accessibility.
• JS properties optimization
• CSS optimization

Define new events

• animating-changed - Fired when the animating property has changed.
• end - Fired when the carousel has reached the last slide.
• end-changed - Fired when the end property has changed.
• selected-changed - Fired when the selected property has changed.
• selected-item-changed - Fired when the selectedItem property has changed.
• show-next-changed - Fired when the showNext property has changed.
• show-prev-changed - Fired when the showPrev property has changed.
• swiping-changed - Fired when the swiping property has changed.
• total-changed - Fired when the total property has changed.