Support first-class continuations in SchemeInterpreter

[noahvanes]

While the concrete Scheme interpreter now uses TailCalls to avoid StackOverflowExceptions, it is still does not allow for reification of its continuations. This is necessary to support first-class continuation values and the corresponding Scheme primitive call/cc (which is already support by our ModF analyses).

Therefore, it might be necessary to rewrite the concrete Scheme interpreter manually in CPS-style.

[jevdplas]

A Scheme interpreter in CPS style has been added in 3703787