Verifier should report mercy kill

[SimonN]

Lix 0.9.4

Have a replay that doesn't terminate. The verifier will mercy-kill it 5 minutes after the last assignment. If not enough lix were saved by then, it's reported as a failure, even though in interactive mode, without mercy kill, the lix would have exited.

Consider reporting as mercy-killed instead of outright failure.

Discussion on Lemmings forums