If a sigAbort handler handles a sigAbort while a GsFile is being
opened and closed, session state can be lost, resulting in an
error #rtErrLostSessionState.
The problem is related to the way signals are used to implement
GsFile operations on client files. Using server, rather than client
files (openWriteOnServer:, etc) avoids the problems.
Using linked sessions, rather than RPC sessions, also avoids the
problem.
Last updated: 4/9/09