Import upstream 2.3-current-2013-10-16
Merging upstream 2.3-current-2013-10-16.

  - Keep our HTS optimizations to avoid high i/o.
  ! Loose HTS-engine-API 1.05 compatibility. Looking for a script
    to convert voice format
Merge branch 'upstream' version 2.3-current-2013-10-16