The patch allows you to edit multibyte input (do not press TAB it will crash 
zsh). There are some bits missing, and most confusing is {lr,}prompt 
treatment that is still mb and not wc.

No attempt was made to compute screen width, it is silently assumed to 1 for 
all charcaters.

Conversion was mostly straightforward and just mechanical replacement. 
Actually I find wc stuff very easy and suitable for using as internal 
representation in zsh core. But this is separate topic.

I added output functions just as temporary solution. In the long run I really 
expect them be used throughout shell code.

This does not use VARARR as is, I can add it in committed patch if deemed 
necessary. Where can I find more info about it?

Please test it without ZLE_UNICODE_SUPPORT.

I may have got confused by ZLE_CHAR_T vs. ZLE_STRING_T; Peter please get a 
look is usage is right.

Comments?