Add support for full CTCSS and DCS beacon options

[bjpetit]

This change adds the ability to include the tone type specifier to a beacon's frequency info. Today a beacon can include the T{number} field to specify a tone. The APRS spec includes support for CTCSS tone squelch and DCS codes. http://www.aprs.org/info/freqspec.txt With this change the tone argument can be set to a value of the form specified in the spec. For example, specifying a CTCSS squelch of 107.3, the TONE argument can be set to C107, or if a DCS code of 047 is to be specified the TONE value can be set to D047. If the TONE argument in a beacon line is set to just a numeric value, it will assume this is specifying a tone specifier as it always has and will add a leading T to the value specified.

I looked at the decoding path and it appears that the the beacon decode path already understands the different tone leading characters.

This change would imply a documentation change to add these options to the TONE argument in beacon lines.

[wb2osz]

Thank you for the suggestion.