Allow memlimit/timelimit to be set to 0 for unlimited; flush StringIOs/IOs after writing.
Update gemspec to use Standalone v0.3.0.
Require Standalone v0.4.0.
Update $TRUSTED_METHODS.
Use latest Standalone::DummyFS features.
Enable DummyFS instead of duplicating part of it.
require() the absolute path to sicuro/version to avoid issues.