Added build_structure capability for page
Implemented control widget.
All widget-specific data now travels in a serialized hash.
code cleanup
Merge branch 'master' into alexmain

Conflicts:
	app/controllers/pages_controller.rb
	app/controllers/widgets_controller.rb
	app/models/content_widget.rb
	app/models/control_widget.rb
	app/models/page.rb
	app/models/widget.rb
	app/views/pages/index.html.erb
	app/views/pages/show.html.erb
	app/views/widgets/show.html.erb
	test/fixtures/pages.yml
	test/fixtures/widgets.yml
	test/unit/page_test.rb
	test/unit/widget_test.rb