Changes from 20020922 (other than bug fixes) are:
* The code to display compound objects was rewritten to make it easier
for runtime extensions to reuse this code.
* A change was made to allow runtime builtins to be notified when a
signal is received so that cleanup can be performed.
* User applications can now trap the ALRM signal. Previously, the ALRM
signal was used internally and could not be used by applications.