fix encoding
improve output for tests using _check_file_lines()
_check_file_lines() will try to pick a source file if none given

typical use case:

    theme_ok( -p ) for @themes;
new subtest: subtest_encoding
cleanup commented out code
avoid a warning when $VERSION is not set
fix pod
update the "UPDATE" section of the README

fix RT #77057

https://rt.cpan.org/Ticket/Display.html?id=77057
new contributor: Olivier Mengué
the extract() method for MultiList themes with a remote list now accept a second parameter

This second parameter is the theme category, which now allows
the extract() method to process different source URL differently.

Caveat: the code does a reverse mapping of URL to category,
so it will break when two categories have the same URL but
process it differentely (a very likely scenario).

This needs to be fixed.
simplify the code by removing the reverse mapping
let meta die loudly if a theme can't be loaded
add an =encoding line
add support for Æ/æ transliteration

and remove cases handled by tr_accent
link to meta

this if a fix for RT #77060
Changes for v1.001
avoid conflicts by prepending test themes with ams_test_
Changes for v1.002
add an =encoding line in files with non-ascii content
move the =encoding command at the top