libhpcalcs: portable (Windows / MacOS X / Linux) connectivity kit library

[LarsF]

It's build from master,
This is when try to get a screenshot type 8

hpcalcs INFO: prime_send_data: q:0 r:3
hpcalcs DEBUG: Dumping OUT packet with size 4
hpcalcs DEBUG: 00 00 FC 08
hpcables INFO: cable_prime_hid_send: wrote 0 bytes
hpcalcs INFO: prime_send: send succeeded
hpcalcs INFO: prime_send_data: send remaining succeeded
hpcables INFO: cable_prime_hid_recv: read 64bytes
hpcalcs DEBUG: Dumping IN packet with size 64
hpcalcs DEBUG: FF 00 00 00 F4 22 73 31 20 00 0E 00 03 00 00 00
hpcalcs DEBUG: 00 00 02 00 00 00 00 00 60 00 27 31 00 00 00 00
hpcalcs DEBUG: 00 00 00 00 00 00 00 00 20 00 00 00 00 00 00 00
hpcalcs DEBUG: 00 00 00 00 00 00 00 00 78 DC 69 31 44 13 6A 31
hpcalcs ERROR: prime_recv_data: skipping packet starting with 0xFF
hpcables INFO: cable_prime_hid_recv: read 0bytes
hpcalcs INFO: prime_recv_data: breaking due to short packet (1)
hpcalcs INFO: prime_recv_data: shortening packet from 0 to 0
hpcalcs INFO: read_vtl_pkt: empty packet
hpcalcs INFO: calc_prime_r_recv_screen: packet is too short: 0bytes
hpcalcs ERROR: calc_prime_recv_screen: r_recv_screen failed
hpcalcs ERROR: hpcalcs_calc_recv_screen: recv_screen failed
hpcalcs_calc_recv_screen failed
hpcalcs INFO: Unhandled packet format