[aprssig] New DSTCALL => software mappings

[Cap Pennell]

Some guesses added to Hessu OH7LZB's numbers below.  Lots of digipeaters and
unattended transmitters!  Numbers of stations seeing packets/maps/messages
versus Numbers "xmit only"?  <sigh>
73, Cap

>    APU25N    13351 UI-View32
>    APRS       1860 possibly old digis
>    APT311     1584 TinyTrak v3.11
>    APAGW      1575 AGWTracker
>    APNU19      918 UIDIGI v1.93 digis
>    APU16N      851 UI-View16
>    APOTC1      664 OpenTracker OT1+
>    APJI23      556 javAPRSSrvr
>    APN382      421 KPC-3 v8.2 digis
>    BEACON      399 tncs, abandoned; local initiative
>    APOT02      391 OpenTracker
>    APX190      350 XASTIR v1.90
>    APOT2A      331 OpenTracker T2-135
>    APS228      328 APRS+SA v2.28
>    APN383      320 KPC-3 v8.3 digis
>    APN391      281 KPC-3 v9.1 digis
>    APT310      263 TinyTrak v3.10
>    CQ          249 tncs, default Unproto ToCall
>    API282      237 Icom IC-2820 (D-PRS,D-STAR)
>    APX192      228 XASTIR v1.92
>    APDPRS      220 D-STAR
>    APX193      209 XASTIR v1.93
>    APC102      206 APRS/CE v1.02
>    APW251      190 WinAPRS v2.51
>    WIDE1-1     178 UI-View32, misconfigured Unproto address
>    APZ186      177 UIDIGI v1.86b digis
>    RELAY       175 clueless (UI-View Unproto misconfigured in UK ?)
>    APZMDR      156 Finnish HaMDR tracker
>    APW285      155 WinAPRS v2.85
>    APERXQ      154 PE1RXQ tracker