Added missing fields.

 On branch rails4
 Your branch is up-to-date with 'origin/rails4'.

 Changes to be committed:
	modified:   db/migrate/053_create_nodes.rb
Renamed delete_signup to destory_signup to be better aligned with the
Rails conventions.

 On branch rails4
Going back "Removed add_signup_topics_staggered as it relied on the view to decide if the assignment had staggered deadlines - better to have the controller decide this."

This reverts commit e2254ac274b6b75ebd10014e4d42dc021b2b4e61.

Conflicts:
	app/controllers/sign_up_sheet_controller.rb
	config/routes.rb

 On branch rails4
 Your branch is up-to-date with 'origin/rails4'.

 Changes to be committed:
	modified:   app/controllers/sign_up_sheet_controller.rb
	modified:   app/views/tree_display/actions/_assignments_actions.html.erb
	modified:   config/routes.rb
	modified:   test/functional/sign_up_sheet_controller_test.rb
Unwound several code merge issues.

Finally got the staggered stuff removed, got destroy everywhere and
added the create_signup.

 On branch rails4

 Changes to be committed:
	modified:   app/controllers/sign_up_sheet_controller.rb
	modified:   app/views/assignments/_reserve_topic.html.erb
	modified:   app/views/sign_up_sheet/_reserve_topic.html.erb
	modified:   app/views/tree_display/actions/_assignments_actions.html.erb
	modified:   config/routes.rb
	modified:   db/migrate/053_create_nodes.rb
	modified:   test/functional/sign_up_sheet_controller_test.rb
	modified:   test/functional/signup_controller_test.rb
Merge branch 'rails4' into jg