msp: fix invalid command exit.

Signed-off-by: Daniel Stodden <daniel.stodden@gmail.com>
msp: decode ident capability bits.

Signed-off-by: Daniel Stodden <daniel.stodden@gmail.com>
msp: redo err/ok command output.

Signed-off-by: Daniel Stodden <daniel.stodden@gmail.com>
msp: add status command.

Signed-off-by: Daniel Stodden <daniel.stodden@gmail.com>
msp: better attitude field naming.

Signed-off-by: Daniel Stodden <daniel.stodden@gmail.com>