Version 1.2.0

• Noise floor and signal level estimates are now computed and printed in
  message headers.
• Added --freq-as-squawk option which uses squawk field in the Basestation feed
  to convey HFDL channel frequency on which the position information has been
  received.
• The program can now decode data from I/Q samples piped onto standard input.
  This allows interoperation with I/Q data sources like GNURadio or KiwiSDR.
• Added --read-buffer-size option for setting input buffer size when decoding
  from an I/Q file or from standard input.
• Slightly better sensitivity.