OK I wanted to be able to query ctags for supported
languages and then for what tags are available for a
given language so that I could stop hard coding these
things into other scripts.
The first --list-languages produces a list of all the
supported languages, one per line.
The second, --list-kinds=<language>, takes a language
and returns all tag kinds that are supported for it.
Diff file was created against a unpatch ctags version 5.4.