Log Message:
Update to 2.2
 - depend on sox instead mpg123
 - in pthai.el, use sox as sole audio player. this simplifies things a bit
   and allows silences to be stripped from audio files while playing.
   remove pthai-mp3-* custom variables
 - minor pthai.el clean ups
 - remove seq-contain-p from pthai.el, which appears deprecated
   in later emacs versions
 - in pthai.el, work around apparent emacs bug when unsplitting
   and buffer name contains combining characters