Revert "Took out the RMI stub/skel compilation."

This reverts commit 4b72465f011018f9ee4ed856a2a7971f7945b9b6.

One of our users on Debian was having problems running the Ganymede
client with javaws.  I'm guessing the OpenJDK install he is using is
refusing permission for the RMI system to create its own RMI proxy
classes on behalf of the Ganymede client.
Add rmi Stub classes back into client jar

Needed since one of our users has a Debian environment in which
the Ganymede client is apparently refused permission to generate
the client-side proxies at runtime when Ganymede is launched via
javaws.  Sigh.