Allow for setting max memory / runtime settings

[Raynos]

This requires checking in 3 languages, something like

setInterval(() => {
  const ht = process.memoryUsage().heapTotal
  const mb = Math.round(ht / 1024 / 1024 * 100) / 100)
  if (ht >= MAX_MEM) process.exit(EXIT_CODE)
}, 512)

setTimeout(() => {
  process.exit(EXIT_CODE)
}, MAX_RUNTIME)