The documentation still points to /etc/ganeti/remote-commands,
although the code is already using restricted-command. Update the
documentation and a few docstrings accordingly.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This is a first design for executing commands via RPC.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>