Timeout handling

Monitor [OK]

Implement more options to spawn/3

src_predicates [OK]
src_list [OK]

Handle syntax errors in src_* predicates

Cleaning up after actor termination

Link

What about running children?
What about propagating?

Crash in engine_destroy:

Create engine
catch(thread_signal(Pid, abort), _, true),
engine_destroy(Pid).

Engine aliases are not alias:

engine_create(x, true, Id, [alias(xx)]), engine_next(xx, N). --> Engine is not current, but recreating fails as the alias is not deleted.