Log Message:
Update to 2.28
all changes for pthai.el
- add option for looking up, viewing words/missed words in pthai-practice-words
- add pthai-dictionary-clear
- bind pthai-complete-word to key like alt-tab for ispell
- for pthai-practice-* functions, don't require dictionary format
- simplify pthai-dictionary-read-file and its *Messages*
- update external dictionaries to latest builds