Makes legacy byteWrite() and interruptWrite() more compatible with pyusb 0.4.x
Makes legacy byteWrite() and interruptWrite() more compatible with pyusb 0.4.x

PyUSB 0.4 has a very flexible input buffer treatment. This change does
not mimic it for all, but make legacy module more close to it.

rabryan/pyusb,AlanJAS/pyusb,swinman/pyusb,swinman/pyusb,h3nj3/pyusb,makerbot/pyusb,kopchik/pyusb,h3nj3/pyusb,rabryan/pyusb,karlp/pyusb,makerbot/pyusb,kopchik/pyusb,karlp/pyusb,AlanJAS/pyusb