* Add multilingual support for utf-8.
* Use japanese as a test case (removing the old tentative support).
* A number of shortcomings affect this code.
+ Bugs :
- This splits algorithms used to determine the length of a string
and to render it in two: either the string starts with an ascii
char and the monobyte, variable-space algorithm is used, or it
does not and a multibyte but fixed-space algorithm is used.
This shortcoming also exists in the code to support chinese.
- From the above comes the biggest limitation: any string that
starts with an ascii character but include non-ascii characters
will not be rendered correctly.
- This does not and cannot support chars outside the BMP. This
probably won't matter, ever.
+ Todos, fixmes, wishlist :
- Single-width characters with diacritics are reported as
double-space chars. It doesn't matter too much at the moment, but
should be fixed in the future.
- Font support currently only includes japanese.
+ Performance and compatibility notes :
- Chinese code has not been switched to utf-8, to maintain backward
compatibility. We should switch it at some point in the future,
but ponder the right way to do it first.
- Retaining the support for chinese with a non-international
charset hurts performance (by making some methods uselessly
virtual).
* Still, this generally works and is extensible (it can be used to
implement korean, traditional chinese, etc, without any more code).
Implementing languages with diacritics needs an improvement of the
bool doubleWidthChar() method.
