v1.6.0

- Fixed bug with 250kHz and 500 kHz TX filtering
- Adjusted FSK timestamp calibration in RX for accurate RX/TX alignment
- Added lgw_abort_tx() function to stop a TX at any time (scheduled or ongoing)
- Added support for user-settable FSK sync word (same for RX and TX)
- Added support for the Chinese 780 MHz band
- Added support for Kerlink 433 gateway
- Added support for Cisco 433, 470 & 780 MHz concentrators boards