Add option do drop new tasks to the timeline from an external component

[Remco4EF]

Is your feature request related to a problem? Please describe.
We want to be able to drop tasks from an external list of items to the timeline. And plan it afterwards.

Describe the solution you'd like
With interactjs it is not to difficult to receive the dropped object. Only the Timeline should tell me which x and y components translate to which group and time.

The timeline component should provide a callback that gives these values back