simplify roles organization and renames

roles/celerity/tasks/main.yml

roles/conf/defaults/main.yml

roles/conf/tasks/main.yml

roles/init/defaults/main.yml

roles/locale/tasks/main.yml

roles/logs/defaults/main.yml

roles/logs/tasks/main.yml

roles/manager/defaults/main.yml

roles/mediaimport/defaults/main.yml

roles/mediaimport/files/mediaimport

roles/mediaimport/files/mediaimport.py

roles/mediaimport/files/on-upload

roles/mediaimport/files/on-upload.go

roles/mediaimport/handlers/main.yml

roles/mediaimport/meta/main.yml

roles/mediaimport/tasks/main.yml

roles/mediaimport/templates/mediaimport.json.j2

roles/mediaimport/templates/sftp_config.j2

roles/mediaserver/defaults/main.yml

roles/mediaserver/handlers/main.yml