For testing non-core files, just `load ../test_helper_libs` after `load ../test_helper` instead of trying to guess which libs must be loaded, in which order, for testing to succeed.
`_command_exists` spews log messages, so our test log is littered with `_log_debug not found`. This fixes that too.
`tr 'A-Z' 'a-z'` will only convert non-accented characters. Switching to
`[:upper:]` and `[:lower:]` adds support for accents.
See https://github.com/koalaman/shellcheck/wiki/SC2018
Additionally, printf's character splitting does not support accented
characters, so output isn't as expected. Using bash's variable expansion
syntax instead will correctly get the full accented character.
John D Pell
buhl
Noah Gorny
Nils Winkler
Zhao Li
Dan Wendorf