e80b07167c
* Regression tests for the GSM 03.38 message class behind sms.flash * Read the GSM 03.38 message class where the spec puts it, and refuse a flash message no alphabet can carry * Keep the code span in the message-class decision on one line * Stop offering the flash message class as an alphabet, and check the encoding option by name * Settle every refusable send option in one check, and record what the review left open * Say what the flash refusal and the encoding option actually do * Keep the README off the alphabet whose long messages do not fit