[aprssig] APRS Symbol Look Up Table

[John Langner WB2OSZ]

Here is another way to get a list of symbols but without the icons.  Run
direwolf with the -S (upper case S) command line option and it will print
all the symbol codes and quit.  This is not hardcoded into the application.
It reads the standard symbolsX.txt and symbols-new.txt files, parses the
relevant lines, and prints in a variety of formats:

* Two character table(or overlay) and symbol code.
* GPSxyz equivalent for use in the destination field.
* GPSxnn equivalent for use in the destination field.
* APRStt tone sequence.
* Description.

Total result is around 400 lines.  Here is a small sample:

        PRIMARY SYMBOL TABLE

sym  GPSxy  GPSCnn  APRStt  Icon
---  -----  ------  ------  ----
 /!     BB      01  AB101   Police, Sheriff
 /"     BC      02  AB102   reserved  (was rain)
 /#     BD      03  AB103   DIGI (white center)
 /$     BE      04  AB104   PHONE
 /%     BF      05  AB105   DX CLUSTER
...(much omitted)...

        ALTERNATE SYMBOL TABLE

sym  GPSxy  GPSEnn  APRStt  Icon
---  -----  ------  ------  ----
 \!     OB      01  AB201   EMERGENCY (!)
 \"     OC      02  AB202   reserved
 \#     OD      03  AB203   OVERLAY DIGI (green star)
 \$     OE      04  AB204   Bank or ATM  (green box)
 \%     OF      05  AB205   Power Plant with overlay
...(much omitted)...

        NEW SYMBOLS from symbols-new.txt

sym  GPSxyz  GPSxnn  APRStt   Icon
---  ------  ------  ------   ----
 /<     MT      C28  AB128    motorcycle
 \<     NT      E28  AB228    Advisory (single gale flag)
 /^     HV      C62  AB162    LARGE Aircraft
 \^     DV      E62  AB262    top-view originally intended
 A^     DVA          AB0622A  Autonomous (2015)
 D^     DVD          AB0623A  Drone   (new may 2014)
 E^     DVE          AB0623B  Electric aircraft (2015)
 H^     DVH          AB0624B  Hovercraft    (new may 2014)
 J^     DVJ          AB0625A  JET     (new may 2014)
 M^     DVM          AB0626A  Missle   (new may 2014)
 P^     DVP          AB0627A  Prop (new Aug 2014)
 R^     DVR          AB0627C  Remotely Piloted (new 2015)
 S^     DVS          AB0627D  Solar Powered  (new 2015)
 V^     DVV          AB0628C  Vertical takeoff   (new may 2
 X^     DVX          AB0629B  Experimental (new Aug 2014)
...(much omitted)...
 /w     LW      C87  AB187    Water Station or other H2O
 \w     SW      E87  AB287    flooding (or Avalanche/slides
 Aw     SWA          AB0872A  Avalanche
 Gw     SWG          AB0874A  Green Flood Gauge
 Mw     SWM          AB0876A  Mud slide
 Nw     SWN          AB0876B  Normal flood gauge (blue)
 Rw     SWR          AB0877C  Red flood gauge
 Sw     SWS          AB0877D  Snow Blockage
 Yw     SWY          AB0879C  Yellow flood gauge