Tooltip default

This is a small patch, that calculated the tooltip ID from the connections.
It is enabled by setting the ID to "default". 

Not sure id this is the best way. We could also remove the drag entirely but then we need a key for no- tootips. 
We can also define that an empty ID means default.

If we finally have the original button layout we might need to change some tooltips IDs, to match with them on generated from the connection. 

What do you think about this? 

 
IMO the template is confusing since the first two arguments fetch from different namespace. I would expect:

left_right_click,play,play,foo  to use the same string for play both times in the template.

Is there a reason we can't make them one namespace? 

```left_right_click,play_title,play_description,foo_description```