Ref T920. D19937 provides about 100 lines of code which can do essentially everything here; throw out the trillion lines of full external API stuff.

(I am generally not sure why everyone writes API libraries like this instead of like D19937.)

Send SMS messages with D19937, so I don't think we need any of this code anymore. This code is techncially reachable through some pathways like bin/sms, but won't be for long.