Log Message:
Changes 0.12.1:
* Make ASS drawings with an extremely high number of control points work
  This change increases compatibility with VSFilter.
* Bugfixes
  * Fix a crash when using newer harfbuzz versions
  * Load embedded memory fonts correctly
  * Large shadow offsets rendered incorrectly
  * Fix incorrect closing of last drawing contour
  * Fix issues with undefined behavior in shifts
  * Lots of of malloc() error checking