Basic job-offer form.
Eliminate duplicate sections code in job-offer form.
Add label attribute to Fields.
Add grouping feature to Form class.
Adjust form label width to fit text.
Create RadioField.
Simplify label styles.

Add "field-label" class to all normal labels and "radio-label" class
to those associated with radio-buttons, and style those classes
instead of the <label> element.

This way we don't need to take the extra effort to undo the styles
applied directly to <label> element.