Receive EStop Notification immediately

[driip-ddrop]

I am building an android application for the Temi Robot and wish to be able to receive the EStop notification the moment someone presses the emergency button on the robot. Currently, I am filtering for errors with "1003" code as an indicator for EStop. However, this error is not sent immediately upon triggering the emergency button (the delays can go up to 5 minute which is too long). Are there any other methods for this?

[zjn0505]

A proper estop callback will be added in next version.

#462