Simulate: run the simulation even if fees are too low, report the underage

[jannotti]

Some contracts might want to spec that they require the caller to pay fees for inner transactions, and the number of inner transactions might depend on chain state. So it would be useful to simulate the call, find out how much it would have cost, and then include that in a real call.

A reasonable work-around is to make the simulate call with an extra 1algo fee (really, 256*minFee would be sufficient) and then examine the simulation response to determine how many inners were actually called. Multiply by minfee, and you know how much you actually need to include.