Various fixes and enhancements

[hn]

The binary representation of the measured values is wrong (right shifted 1 bit):

root@bare-rasberripi:~/hx711# ./hx711
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 1 1 1 1 1 1 0 0 n:       7672     -

This patch formats it like this (7672 = 1110111111000):

root@bare-rasberripi:~/hx711# ./hx711
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 1 1 1 1 1 1 0 0 0 n:       7672     -

Please see my fork (https://github.com/hn/hx711) for more enhancements and features.