JS Style Guide: Add rules for constructor invocation

Ref https://github.com/jquery/jquery/pull/1856#issuecomment-65346516

These reflect my personal preference for explicit clarity (especially around whitespace-preceding keyword operators) and could easily be changed; I just want to get some clear guidelines published.
Should this apply to every object including native objects? This might be misunderstanding in cases like setting new arrays with `[]`and regexps with `/`... 

Maybe a more clear statement should be: 

*When invoking constructors, they should always be invoked as functions (e.g., with argument lists), even when _not_ supplying arguments.*