Preliminary support for rule type "Z"

"Z" is used when the dependency hinges on the number of boxes checked.
This commit deals with preliminary support for the "Z" rule.
This change ensures that if "Z" is among the dependency conditions, it
does not get stepped on by the algorithm for parsing rules in update_logic.
	modified:   lib/assets/javascripts/surveyor_gui/surveyor_gui.js
Fixed answer sorting a second time.

Missed an issue after sorting and saving.  Revamped approach.

	app/views/questions/_answer_fields.html.erb - added a hidden
	field for answer.id

	lib/assets/javascripts/surveyor_gui/surveyor_gui.js - added a
	method to iterate through answers and update the display order
	to match the position in the DOM.  Run after a user sorts the
	answers and after replacing the answers partial.

	lib/surveyor_gui/models/answer_methods.rb - eliminated an
	unecessary method to update display order.
Cleanup from changing answer sort

	app/controllers/answers_controller.rb - removed unnecessary
	sort method.

	config/routes.rb - removed unnecessary route for answer sort

	lib/assets/javascripts/surveyor_gui/surveyor_gui.js - removed
	commented out call to answer sort.