use string formating to create topic

Signed-off-by: Steven Armstrong <steven.armstrong@inf.ethz.ch>
more complete example for req/rep to control socket

Signed-off-by: Steven Armstrong <steven.armstrong@inf.ethz.ch>
initial version of logger config controller that can be configured by sending it messages

Signed-off-by: Steven Armstrong <steven.armstrong@inf.ethz.ch>