drop wrong migration 20140801080705
add corrected migration for adding dummy user to events without users
fix for buggy migration 20140801080705
fixes
create dummy user if not found
add attr_accessible for TempUser
Use find_or_create_by for the deleted user
Merge pull request #480 from hennevogel/blah

Drop and fix wrong migration 20140801080705
remove attachments
remove jquery-fileupload-rails
add links for events/conferences/submitters
fix []
fixes from comments
Merge pull request #376 from differentreality/speakers

add links for events/conferences/submitters
Merge pull request #458 from differentreality/remove_attachments

remove attachments
 Big refactoring of registration

- Added datatable gem
- Addaed datatable to events, users (#422), registrations
Merge pull request #471 from ChrisBr/refactoring_registration

Big refactoring of registration
Refactoring ticket purchase [skip ci]