Display friendly error message if invalid bounce time used with pigpio backend

[lurch]

As talked about in #826 the "bounce time" value in pigpio is actually a "glitch filter", and has a much smaller maximum-value than the debounce time in RPi.GPIO.

We should probably check for this in GpioZero and display a "GpioZero exception" rather than letting the exception from pigpio bubble all the way back up to the user. (and optionally, explain this difference in the documentation?)