Log Message:
Version 3.21.67
  * Maintenance release

RTTY FSK modem
  * This patch contributed to by
    W1HKJ, Dave Freese <w1hkj@w1hkj.com>
    DO2SMF, Stefan Fendt <smfendt@gmail.com>
  * Waveshaped FSK modem for classic RTTY using raised cosine
    matched filters
  * Kahn demodulator
  * RTTY scope based on separate mark / space filter outputs
  * Corrected s/n estimator
  * Change RTTY browser to new demodulator
  * Fixed missing browser highlight for callsign detection
  * Bypass Viewer signal processing if viewer(s) are not visible
    - significantly reduces % CPU use
  * Separated psk-rtty range/value pairs for viewer squelch
    control.

PSK viewer
  * Suppress psk viewer decoding if neither viewer
    is visible.

Contest fields
  * increased size of contest fields

RigCAT INIT/CLOSE
  * This modification submitted by:
    Arvo Jarve, ES1JA, <arvo@softshark.ee>
  * Added CLOSE port rigcat command
  * Added user control to enable/disable restortation
    of serial port status bits when closing port
    - use <RESTORE>bool_value</RESTORE> in xml definition
      file.

Olivia FEC reset
  * Added user control to enable/disable automatic reset of
    FEC integration depth when BW / Tones are changed either
    by user or via RsID reception.