Export to all formats seems to work well after removing the "ps2pdf"
option to the hyperref package.
Accordingly we uninvert the tests for the other formats. All ctests
pass on an updated TeX Live 2020.
* "platex" fails with "inputencoding default", if there is text in other languages.
"jis-platex" works fine, "jis-utf8" fails with German Umlauts (maybe more).
* The expert setting "inputencoding default" switches the inpute encoding
with language switches without marking this in the LaTeX source.
It is rarely required (if ever) and makes documents easy to break.
It is not required for AMS Books, Simple CV, ... (probabely a tex2lyx issue).
"utf8" and "auto" work fine.
Re-structure and rename files in a transparent way. Most template/example
names now correspond to the (verbose GUI) name of their layouts.
Note that this, most prominently, also changes [LANG/]splash.lyx to
something less insiderish, namely "Welcome.lyx".