The quadrigraphs change (instead of changequote) is per the advice in the autoconf manual
The conversion to AS_CASE is also per the autoconf manual advice.
Tab conversion is just following existing style per a previous cleanup commit.
I find it useful to display at the end of the configure run the values of certain variables, rather than having to check the generated files or config.status.
Note: As per a discussion with @suominen after a previous pull request, I haven't regenerated configure or aclocal.m4 (etc), because there'd be differences in those from the preferred regen platform (NetBSD with specific pkgsrc packages), unless I have exactly the same versions of all the tools and dependencies (autoconf, iconv, etc), which I haven't got around to setting up in a build environment yet. Therefore, this merge will require a separate regen commit after the merge.
A few more improvements to
configure.ac:AS_CASEis also per the autoconf manual advice.configurerun the values of certain variables, rather than having to check the generated files or config.status.Note: As per a discussion with @suominen after a previous pull request, I haven't regenerated configure or aclocal.m4 (etc), because there'd be differences in those from the preferred regen platform (NetBSD with specific pkgsrc packages), unless I have exactly the same versions of all the tools and dependencies (autoconf, iconv, etc), which I haven't got around to setting up in a build environment yet. Therefore, this merge will require a separate regen commit after the merge.