exposed low level serialException on usb disconnect

[n1lby73]

While utilizing the library for my application, i noticed there was no way to catch the serial exception once the connected xbee radio is disconnected while my python application is still running. After careful inspection to find out the underlying cause, i noticed that the serial exception was caught from the xbee library but was not exposed for user level.

with this modification the serial exception error has been exposed with the use of a callback function called add_error_callback(callback) through XBeeDevice from digi.xbee.devices

[dazedandawesome]

Hello! Can we approve this? :)

[dazedandawesome]

It probably needs to rename the exec to exc

[n1lby73]

It probably needs to rename the exec to exc

on what line please

[n1lby73]

Hello! Can we approve this? :)

sure you can