Smarter range parsing
Smarter range parsing

It used to return (0, None) when one of the 2 values was invalid (not an int).
Now it defaults the start byte to 0 if invalid, and the end byte to None,
independently.

maurodelazeri/shiva-server,tooxie/shiva-server,maurodelazeri/shiva-server,tooxie/shiva-server