relax SVN archive

The multi/test_implementation2.py script can now be run in uni-processor mode.

Thought it still fails due to deficiencies in the Processor base class (one of Gary's TODOS in the
Multi_processor class).

Comment fixes.

The multi/test_implementation2.py script now properly uses pre-send data in the slave calculations.

The sending component is complete (though is still non-functional on the uni-processor). However
the handling of data post-calculation still needs to be abstracted via the API.

Partially implemented the Processor.data_update() method.

This now should work when the rank argument is not supplied.

Removed the Test_slave_command_presend class as the multi-processor API is now simpler.

The single line data_update() API function call is now used instead.

Created the special command object Slave_storage_command for transferring data to slaves.

This command currently has two special methods:
- add(), used by the master processor to add data to the command for transfer.
- clear(), used by the slave (via run()) or the master to clear out all data.

Split the multi.commands module into two - the slave commands and result commands.

This rearrangement is only for code clarity.

Removed the Mpi_processor.data_upload() method as this will be done at the Processor level.

Shifted all of the processor command objects into the multi.commands module.

The other multi.api module objects have been shifted into the multi.misc module.

The multi-processor package now allows sys.exit() calls within the master processor.

This affects all processor fabrics, as the Processor.run() method has been modified. The SystemExit
exception is now specifically caught on the master. The Processor.exit() method is then called to
allow the specific fabric to clean up, if needed, and then the SystemExit is re-raised to allow the
system exit to proceed as normal.