Improve overheating error messages #34
Description
Right now, when the sonar overheats, the driver produces the same error messages as it does when the sonar is not pinging. This is particularly amusing since setting it to not ping is the way we prevent overheating.
In order to prevent this log message from spamming the roslaunch raven_config robot:=true console into uselessness, we've downgraded it to LOG(DEBUG). (Since we're using g3log in this part of the driver, we didn't have the option to use ROS's throttled logging API.)
This isn't ideal -- we'd like to actually know that the sonar is overheating.