New/Edit Plane dialog has poor CSS on checkbox inputs

[bovine]

The dialogbox to add or edit a plane has CSS that forces the width of all input elements, including checkboxes, causing the display of the Hidden and Retired checkboxes to be suboptimal.

in screen.css:

#popup table.single_column input, #popup table.single_column textarea, #popup table.single_column select {
    width: 200px;
}