General improvements and fixes

This release is all about improving your app experience:

• The app is now better optimised for larger devices and tablets/iPads.

• You can now go directly to the list a task belongs to, from the task's screen.

• If you make changes to a task or a list, and press the back button without having saved your changes, we'll now show you a confirmation dialog to prevent you from losing your changes accidentally.

• Various under the hood fixes and improvements