Change to plugin interface: unload() is no longer part of the protocol, and any unloading a plugin needs to do can just be done by registering an atexit handler.
Change to plugin interface: unload() is no longer part of the protocol, and any unloading a plugin needs to do can just be done by registering an atexit handler.

git-svn-id: b6fd099cd3d97ba56ca68c4d1ea7aaa6a131ba03@17 8b7adc99-b347-0410-ae0a-d9e86c8d69b5

roderyc/enso,roderyc/enso,roderyc/enso