Removed Observe aliases from Signal and Events. The had no benefit as Observe cannot be chained further.
Made AddDummyArgWrapper more flexible w.r.t. to const argument refs.
Streamlined API. Fold is now Iterate, old Iterate has been removed. The case where the old Iterate would be needed is now covered by the overload for token streams. Shuffled some parameters around for consistency.
Removed special handling of token streams that would allow their value being omitted from client function signatures. Instead, an unnamed parameter of type "Token" can be declared.
This makes it easier to identify token streams, the extra boilerplate is minimal and the API is simplified.