Add repeaters to supported question types.
	modified:   app/helpers/question_helper.rb - modify to allow for
	repeater.

	modified:   app/views/question_groups/_form.html.erb - add repeater
	to collection of question_types.

	modified:   app/views/questions/_form.html.erb - add repeater to
	collection of question_types.

	modified:   lib/assets/javascripts/surveyor_gui/surveyor_gui.js -
	add repeater to question_types that call render question_group.

	modified:   lib/surveyor_gui/models/question_type_methods.rb -
	add repeater question type and related sub question types.

	modified:   README.md - modify limitations to exclude repeaters.

	modified:   lib/surveyor_gui/models/question_group_methods.rb - modify
	question_type_id setter.