Due to the fallthrough the warning would be printed in any case when using
UTF-8 and not only if the BOM is actually written (as there are non-ASCII
characters). This problem became apparent when using the tageditor's CLI
with `--id3-init-on-create` to create an ID3v1 tag from ID3v2. Of course it
doesn't help if there are actually non-ASCII characters present.
1. Convert TYER and related fields of old ID3v2 versions to the new TDRC
field and only expose that via the generic accessors.
2. When writing an old ID3v2 tag, convert TDRC back to the old fields.
3. One can still manually unset the via 1. auto-populated TDRC to disable 2.
and write the old fields directly. So the automatic handling does not
reduce the flexibility of the library.
4. Deprecate 'Year'; it is replaced by the already existing 'RecordDate'
which is now supposed to be used everywhere where 'Year' was used before
5. Introduce 'ReleaseDate' to support this field which is supported in
ID3v2.4.0 and Matroska via the generic accessors.
6. Use ISO format when converting tag values of the type DateTime to/from
string. This is closer to what's used in ID3v2 tags internally. (The
library still allows the old format as fallback when parsing for
compatibility.)
since it is apparently used by some software.
But
* Write at least a BOM so it can be interpreted later
correctly as UTF-8
* Print a warning
* Keep proposing Latin-1
The tag editor should allow to configure which encoding
is used and whether the BOM is used and which encoding is
assumed when parsing a file.
