This adds a way to dynamically change the static RAM limit of a script,
which is also its current RAM usage. This makes it possible for scripts
to dynamically change their memory footprint, opening up new strategies
beyond current ram-dodging.
Calling functions still permanently increases the *dynamic* memory
limit; RAM-dodging is still the optimal strategy for avoiding RAM costs,
in that sense.
This also adds dynamicRamUsage to the info returned by
`getRunningScript`, to allow introspection on the currently needed ram.
