Regressions on OLPC XO

[quozl]

With SUGAR_SCALING of 100, and org.sugarlabs.font default-size set to 7.0, on 1200x900 resolution, several problems appear.

• [ ] the dimensions radio buttons do not fit on the toolbar, forcing the stop button to a submenu.
• [ ] two of the new icons do not render properly,
• [ ] entering a conversion causes the main window to grow.

Tested with 5ad6553.