[BUGFIX] package:* commands no longer issue a fatal error
Most package:* commands and sometimes also the flow3:cache:flush
command issued a fatal error. The actual command was executed
successfully, but the SignalAspect caused a fatal error because
the proxy code cache had already been flushed and therefore
FLOW3 was in an unstable state.
Those commands which flush the code caches will now exit right away
to avoid any further code execution.