Challenge validations
Add public flag to tournament
Add InviteRequest model
Destroy invite requests automatically with parent
Add ability to request invite
Add can_join? and can_request_invite? to tournament
Tweak and clean up a bit
Add contextual admin for tournaments
Add minimum working admin UI for invite requests

and tests for new tournament instance methods
Fix can_join? for owner & failing integration tests

Also moves "Invite player" tab back out of Admin
Clean up update on invite request controller
Require self last to override everything else
Refactor all badges to use new badge helper
Make information page public
Switch markdown parser to kramdown
Mail down
Invite request email
Revert schema to master so it wont merge conflict
Merge branch 'master' into statemachine

Conflicts:
	app/controllers/tournaments_controller.rb
	app/helpers/games_helper.rb