Notification icon looks distorted when running at a higher DPI

[davkean]

Repro:

1. Right-click on Desktop, choose Screen resolution
2. Choose Make text and other items larger or smaller
3. Under Change the size of all items, check Let me choose one scaling level for all my displays
4. Change to Larger - 150%
5. Log out and then back in

Looks like we probably need at least a 32x32 version of the icon that @Ianvdl made.

[davkean]

Actually, according to Creating a DPI-Aware Application we should be providing 4 sizes:

16x16 20x20 24x24 32x32

[Ianvdl]

I'll take a look, it might be easier if I convert it to SVG and then choose the sizes afterwards.