JSON object order

Redsea uses the jsoncpp library where each JSON object is an std::map<CZString, Value>. These will be sorted in alphabetical order at printout, because they are iterated using string comparison sorting by the key.

A custom redsea modification to jsoncpp allows us to use a sorting tag that gets removed at printout. A few selected fields will always be sorted to the beginning of the group to make the output more human-readable:

• 00: pi
• 01: rx_time
• 02: callsign, callsign_uncertain
• 03: group
• 04: ps, partial_ps, radiotext, partial_radiotext