[VOTE RESULTS] Make ProcessingException extend CascadingRuntimeException

[Ugo Cei]

Here are the results so far:

Bertrand                +1
Berin           +1
Unico           +1
Stephan         +1
myself          +1
Marc                     0
Geoff            0
Nicola Ken      -1
Leo Sutic               +1 (non binding)
I'll let the vote run for 24 more hours. In the meantime, let me know 
if there are any errors in the summary.

	Ugo