librfn: Set NDEBUG

Some of the librfn library functions use the C library assert() macro
which pulls in quite a bit of dependant code (mostly the stdio library).
We'll just turn it off until we hook up this up to cm3_assert().

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
librfn: Update to latest version.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>
multistomp: Switch to CC messages rather than note on/off

Also introduces a boot animation and an error animation (LEDs flash when
there is a message "stuck" in the USB plumbing.

Signed-off-by: Daniel Thompson <daniel@redfelineninja.org.uk>