Refactor construction of complex questions (grids and inline groups).

Move most of code into QuestionType, so each QuestionType
knows how to build itself.  After save, question calls
question_type.build_complex_question_structure, which know which
structure to build.

Also correctly processes grid dropdown and displays properly on
surveyform.
	modified:   app/helpers/surveyform_helper.rb - allow for
	grid dropdowns

	modified:   app/views/questions/_form.html.erb - puts stars
	back in as a question type.

	modified:   app/views/surveyforms/_question_field.html.erb -
	allow for grid dropdowns.

	modified:   app/views/surveyforms/_question_group.html.erb -
	pass question as a parameter to question_group_class helper.

	modified:   lib/assets/stylesheets/surveyor_gui/surveyor_gui.sass -
	hide table header for grid dropdowns.  Otherwise, format like a
	normal grid.

	modified:   lib/surveyor_gui/models/question_methods.rb - remove creation
	of group question structures.

	modified:   lib/surveyor_gui/models/question_type_methods.rb - add processing
	for complex questions structures (grids and groups).