Most of this is CAP (Cut And Paste) from the Script task
ScriptFilter class, implements TokenFilter.Filter
for scripts to use.
This provides the same beans as the Script Task
to a script.
The script is meant to use get self.token and
set self.token in the reply.
since: Ant 1.6
Called filter the token.
This sets the token in this object, calls
the script and returns the token.
Parameters: token - the token to be filtered the filtered token