event layer

[remyla]

Write an event layer to plug the server to the user actions (create, update, delete, upload etc)

• example: the user action 'drop file' can trigger an 'upload to server' if the 'upload to server' module is activated
• example: the user action 'drop link' can trigger a 'damas.create' on server if activated. returned errors are important
• the event handlers are written in a separate file.