Duplicate / Clone task

[elight]

Along with the "edit" task, a "clone" task could be very helpful for numerous reasons:

1. it would allow for prototype/template tasks that can be cloned and edited faster than created. Imagine if "clone" immediately opened the task editor window and then wrote the clone to the local file
2. For similar tasks, clone and edit could make for significant time savings when the source task resides in another file.

[claremacrae]

Nice idea. Thank you very much.