api-doc: update to latest

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>
add handler for /os/dmesg and add dmesg as a command

A minimal implementation for dmesg.

Signed-off-by: Jaspal Singh Dhillon <jaspal.iiith@gmail.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>