Fix Serializer Calling Private Method

[bert-mccutchen]

The Serializer class is attempting to call the private method marshal_dump for components. This happens when it is attempting to collect instance variables due to a failing dump.

I don't have the time to write a better fix, so i've just moved the method into public scope.

motion/lib/motion/serializer.rb

Lines 68 to 77 in 7e1bc4b

	def dump(component)
	dump!(component)
	rescue TypeError => e
	failing_ivars = []
	component.marshal_dump.each do |ivar_name, ivar_value|
	dump!(ivar_value)
	rescue TypeError
	failing_ivars << ivar_name
	end