refactor RDS modulator parameters and file handling; remove deprecated commands

supported_cmds.txt

@@ -0,0 +1,81 @@
+AF
+AFCH
+DI
+- DPS1
+- DPS1EN
+- DPS2EN
+- DPS1ENQ
+- DPS2
+- DPS1MOD
+- DPS2MOD
+- DPS1REP
+- DPS2REP
+- DTTMOUT
+- EQTEXT1
+- LABPER
+MS
+PI
+PS
+PTY
+PTYN
+PTYNEN
+RT1 | TEXT
+RT1EN
+- RT2
+- RT2EN
+- RTPER
+- RTTYPE
+- RSTDPS
+- SCRLSPD
+- SPSPER
+TA
+- TATMOUT
+TP
+TPS
+INIT
+ALL
+- HELP
+- EON*
+- MSG*
+- DPS2MSG
+- RT2MSG
+- SLIST
+- SEN
+- Sxx*
+(COMSPD)
+CT
+(DATE)
+- ECHO
+(EXTSYNC)
+LEVEL
+(LTO)
+(PHASE)
+(MJD)
+(PILOT)
+RDSGEN
+(RESET)
+(SPEED)
+- STATUS, ??
+(TIME)
+- VER
+- ADR
+- CC
+- DSN*
+ECCEN
+G
+GRPSEQ
+LIC
+- NOHDR
+PIN
+PINEN
+PROGRAM
+- PSN*
+(PSW)
+RTP
+RTPRUN
+SHORTRT
+- SEL
+- SITE
+UDG1
+UDG2
+- UECP