Fix bug
Merge branch 'master' into feature/stamp-attach-interface
Added IF for attaching stamp
Modify status code when validation error occuered
Merge branch 'master' into feature/stamp-attach-interface

Conflicts:
	static/coffee/detail.coffee
	static/js/detail.js
Adjust wall page
Merge pull request #28 from hirata-motoi/feature/stamp-attach-interface

Feature/stamp attach interface