IRC discussion on i18n, xml/utf8, and 1.8->2.0 data migration issues

[Chris Shoemaker]

  I have some comments/proposals that are related to the 1.8<->2.0
compatibility issue and slightly related to the encoding issues.  So,
I'll just jump into this thread.

  GnuCash 1.8 is pretty forward-incompatible, in the sense that it's
not easy to keep the format backward-compatible.  Aside from
encodings, it just bombs on unrecognized xml elements.  :(

  To solve thing for the future, I propose that we let 2.0 at least
_try_ to continue reading a file that contains unknown elements.  That
way, if we're smart about how we extend the format, it will be
backward compatible.

  Unfortunately, that doesn't help for 1.8.  For that, I propose a
"save-as" or "Export" option that will be _sure_ to save a file that
can be opened with 1.8.  For 1.8 compatibility that file would have to
drop new features (e.g. no budgets), and if there turns out to be an
encoding incompatibilty, it can also handle that.

  Note: 2.0 datafiles are mostly 1.8-compatible, but this option would
have to _always_ work.

-chris