v0.4.0

The wallpaper picker now shows a piece as its thumbnail, rather than the app's icon.

Two fixes to things the parallax in v0.3.0 had broken or left inconsistent:

• Text was sized against the whole piece, which is wider than the screen, so it ran off the edge. It is now sized to the strip that is on screen whatever the home screen is scrolled to, and reads in full at either end.
• In the dark theme, a device taking its colors from the wallpaper was painting near-white trails onto black. It now uses calmer mid tones, as the dark theme already did when following a chosen accent.