fix-bug-1108715

[Alan Griffiths]

To reduce future confusion about the mir example binaries their names
are being changed with the landing of
lp:~alan-griffiths/mir/fix-bug-1108715. Vis:

All of them are now prefixed by "mir_demo_".

All of the standalone programs are prefixed by "mir_demo_standalone_".

All of the server programs are prefixed by "mir_demo_server_".

All of the client programs are prefixed by "mir_demo_client_".

To avoid confusion, it would be good to delete any existing binaries
when you pick up this change.