[Feature request] Enhance failure message when binding an already used device

Hello Michael,
 

I use the API to automate some tasks, but I sometimes had failures when binding a device and finally found the reason : it was already in use at this time (I know I can kick someone out of a device, but this is not what I look for).
I noticed that in that case, only a "FAILED" message with no context is returned, whereas errors give explicit ones, just like ERROR: Invalid adress "USE,example.com.42" 
As the information of either a device is already in use is displayed on the UI and accessible trough the INFO ipc, could it be possible for you to add it the to the message, such as "FAILED: Device already in use" (possibly mentionning the user). It would greatly improve user experience.

Thanks for your consideration and for your great work !