Remove sample_pusher stuff, in its own dev branch now
Now 2 samples per received byte, compatible with HDL
1c46189163d4d5dc550b2d2c801f41f9e1880303
Added note about adding modified Piski PID's to USB dev rules
set_fifo_mode and set_uart_mode don't need -lftdi and -pthread,
sample_grabber doesn't need -lftd2xx
set_fifo_mode and set_uart_mode don't need -D_FILE_OFFSET_BITS=64