Poke about with spacing in the contribs form... It still feels busy to me, but adjust...

Poke about with spacing in the contribs form... It still feels busy to me, but adjusts some wrapping issues.
* Space now present between 'Namespace:' label and selector drop-down
* Added no-wrap spans wrapping label and control for the namespace, year,
  and month selectors, so the form is more legible at smaller window sizes where the long lines don't make it through intact