Log Message:
Update to version 2.38
- add force option for 'pthai-message, use switch-to-buffer-other-window
- remove 'pthai-cycle-split-mode, just use customize to set
- make 'pthai-soundfiles-sort work with 'sort, small cleanups
- in 'pthai-mp3-fetch, print download url to *Messages* buffer
- fix 'pthai-download-and-play when force fetching of complete word
  if pieces were previously downloaded
- fix borderline cases in 'pthai-spell-merge-singles
- simplify options to 'pthai-spell-suggestions and 'pthai-unknown-bounds
- change 'pthai-unknown-words-extract to extract words from current buffer
  into new temp buffer, instead of current and named buffers
- modify 'pthai-unknown-words-toggle, add 'pthai-unknown-words-toggle-dictionary
  and 'pthai-unknown-words-toggle-unknown for specific toggling of
  undefined or unknown words
- comment cleanups and corrections in a few places