Allow rendering of a partial, passing in a collection of objects, or a single object, to be assigned to locals in the partial.
The default local name is the name of the partial. ie. _person.html.erb, the local will be 'person'. Local can be overridden.
partial('person', :person => @person, :other_local => 'Hello World!') # Current method
partial('person', :with => @people, :locals => { :other_local => 'Hello World!' }) # Using a collection
partial('person', :object => @person, :locals => { :other_local => 'Hello World!' }) # Single object
partial('things', :with => @people, :as => :person) # Overriding the default local
Patch attached. Specs all pass.
