slave.cpp baudrate register

[sonelu]

By definition a slave device should communicate over the Dynamixel bus, therefore I think it would be logical to include the baudrate as a default register in the class along with the ID, protocol, model number and firmware version.

I would recommend using the register id 8, which keeps it consistent with other devices. Also I would use the mapping table for baudrates based on the latest devices.

I think also we should implement the return delay time, as this is a common feature of the Dynamixel communication and all devices should accommodate it in case the master requires this delay. Typically the return delay time is register 9 that is already used by the protocol, so I suggest we use 10.

I can put a PR if this is ok.

[ROBOTIS-Will]

Hi @sonelu Thanks for the suggestion. I think adding the baudrate and return delay time are good practice as setting up a slave device. I'll review and merge your PR. Thanks!