Label renamed as requested by #15.
New field added to form as requested by #14.
Filter the subtickets by creator as requested in #18.
The content of the notification mail now corresponds to the create/edit form and its labels; as requested in #17.
No longer display the csv export action; as requested in #19.
Display the new issuer field on the detail view and hide empty fields; as requested in the comments of #14.
Renaming the frontend representation of the tickets; as requested per #20.
Merge pull request #31 from 4teamwork/mba_changes

Issues #14, #15, #17, #18, #19 and #20.