UI Overhaul

**NOTE** Upgraded minimum SDK version to 11 from 3 for the purposes of
using more complex widgets.

Mainly working off Add/Edit Task but a few minor tweaks to home task
page.

Icons/layouts/colours further developed to suit modern sdk.

Add "Task Name" field which should maybe take priority focus over "Task
Details" and appear on Task List page as first key indicator.

Experimented with using a number selector instead of number chooser for
time choices but did not seem to be compatible.