Spring cleaning

Getting in before the thaw.

 - Don't override empty-paren methods as paren-less.
 - Be explicit about empty param list calls.
 - Banish needless semicolons
 - Omit redundant val in case class params
 - Don't call `someArray.size`
 - Modernize legacy quoting in scaladoc
 - Address general scaladocrot.

These were a few of my least favourite things.

Review by @paulp