Free42x - HP-IL extensions to Free42

[jch]

Updated sources and binaries available on Github.
- Changes:

• IFC/RFC handshake bug, if first handshake was unsuccessfull, then following handshakes were messy.
• IDY timeout increased, was too short compared to Bluetooth latency on Android.
• Add some tracing capabilities of hpil frame to help troubleshoot, a debug checkbox in HPIL Preferences menu and stored traces will be displayed when tapping this menu again. (Android only)
  

- Some hints on Bluetooth issues I encountered:

• Latency, about 10 ms and inconstancy between different Android releases and devices.
• IFC/RFC handshake & IDY timeout bugs.
• Bluetooth stack on Nexus 4 / Lollipop 5.1.1 seems to break the connexion after about 10 s idle.