* begin implementing support for the V.24 modem as a regular modem dvmhost can utilize;
* add Tx support (maybe);
* theoretical TSBKs via V.24?;
* set start of stream correctly;
* ensure stream frame type is set correctly; send start of stream and end of stream correctly for TSBK (hopefully);
* fix variable naming; ensure voice frames aren't repeated back to the V.24 source;
* document configuration changes;
* add framework for eventual V.24 UDP support;
* correct issue not handling regular modem commands;
* fix up issue writing V.24 data to the modem buffers;
* initial working V24 modem implementation
* update commenting/documentation;
* reorganize configuration parameters and documentation;
* whoops forgot comment;
* ensure TSDU MBF is disabled for DFSI modems; tag DFSI parameters in log output proper for clarity; ensure P25 fixed mode is forced for DFSI modems;
* fixup V.24 UDP port, properly fake certain modem responses, fix bad RTP transmissions; add STT_NON_IMBE_NO_JITTER message type for ignoring message jitter;
* fix data offsets;
* ensure DFSI's internal call timeout is settable;
* bump version numbers;
* use LOG_MODEM not LOG_SERIAL;
* correct issue with PING/PONG resetting pktSeq incorrectly; add metric calculation for determining RTT for a PING/PONG;
* use milliseconds instead of seconds for delta clocking on the FNE and host for networking; correct several issues with incorrect packet sequences being sent for some control packets; correct issue with tracked packet sequence possibly being incorrectly reset;
---------
Co-authored-by: W3AXL <29879554+W3AXL@users.noreply.github.com>
Bryan Biedenkapp