Release v2.2.0

New features:

 - Migrate to another device with a simple QR code
 - Supports wide screens and landscape format for tablets.

Bug fixes:

 * Improves performance (removes unused js library)
 * Removes cache history from export wallet
 * Check from swipe paper wallet if backup has been completed.
 * Fix UI sidebar menu
 * Full amount precision on tx details modals
 * Fix backup scrolling for small devices
 * Fix spinner while create/import/join a wallet
 * Fix preferences UI for some Android versions
