richedit: Store richedit version rather than boolean bEmulateVersion10 value

[Juan Lang]

Hi Dylan,

-  if (!editor->bEmulateVersion10 || (editor->nEventMask & ENM_UPDATE))
+  if (!editor->dwEmulatedVersion || (editor->nEventMask & ENM_UPDATE))

This change is incorrect, as dwEmulatedVersion is never set to 0.  I
believe you mean if (editor->dwEmulatedVersion > 0x100 || ...

I have to ask, though:  what bug does this fix?
--Juan