This function will convert the complete file from Unicode or UTF-8 (ASCII representation) to UTF-8 (with the file internally as Unicode). When the file is saved it will remain as UTF-8 unless specifically converted to another format by the user. The status bar will show "U8-" in front of the file type indicator.
Internally the file will be in UNICODE format and converted back when the file is saved to UTF-8 encoding. In HEX mode the file will be shown with its current internal representation.
