UTF-8 support from previous version switched in; additional alphabet- conditional support added as follows: 

* Correctly converts character index returned from Font_FindCaret into byte
  index into raw string.
* Left-arrow, right-arrow, delete-left and delete-right now act as far as
  the next character boundary, instead of to the next byte.
* Menu item text justification works again (it relies on overwriting spaces
  with hard space characters, which are two-byte characters in UTF-8).
* General key handling code has been rewritten. The Wimp now has three
  internal key input buffers - one each for taking keyboard-generated,
  task-generated, and function-key-generated strings. Each input buffer is
  processed in chunks of one character, rather than one byte; malformed
  UTF-8 characters are rejected, so tasks don't have to worry about them
  (simplifying their character-handling code). There is also a key output
  buffer, to ensure that (UTF-8) sequences of Key_Pressed events are not
  broken up.
* As a...