spanning Text segments to avoid affecting 1st char of 2nd segment
- PDF417/MICROPDF417: add optimized encoding, FAST_MODE for
previous scheme; formatting changes
- common.c/h: add `cnt_digits()`, comments in include and make more
consistent, minor code fiddling
- DOTCODE: replace `dc_n_digits()` with new `cnt_digits()`
- test_qr: fix `test_qr_perf()`
- composite: minor code fiddling
- library: debug dump HIBC-processed input
- BWIPP: update to latest
