A command delimiter option should exist for executing the pre- and postcommands

Current Situation

YADE uses semicolons as command delimiter, i.e.
pre- and postcommands which contains semicolons are splitted in mutiple commands.
For some commands it doesn't make sense, e.g.

echo "hello;world" 

and an error is raised.

Desired Behavior

An option for a different command delimiter should exist.