UI: Take two on the icon stuff.
- 'New Round' is back, with the bell icon
- Switched out the pixmap icons for energy and health for Oxygen battery icons.
* battery-discharging-xxx for health, dropping as the health drops
* battery for energy. No visual representation of the state, except the LCD numbers.

Since both sides now use the same health icon set, I made that static, with an icon-loader function.