Update FreeType to 2.9 version from 2.8.1

Update FreeType to 2.9 version from 2.8.1

2018-01-08
FreeType version 2.9, the first release of a new ‘minor’ series, is now available for download. The main reason for starting a new series is Ewald Hew's GSoC contribution of making Adobe's CFF engine handle Type 1 fonts also, greatly improving the rendering quality of this ancient but still important font format.

If you are going to use variation fonts, please update to this version since it comes with some important fixes. More information on this and other changes can be found here.

https://sourceforge.net/projects/freetype/files/freetype2/2.9/

CHANGES BETWEEN 2.8.1 and 2.9

I. IMPORTANT BUG FIXES

• Advance width values of variation fonts were often wrong.

• More fixes for variation font support; you should update to this
  version if you want to support them.

II. IMPORTANT CHANGES

• As a GSoC project, Ewald Hew extended the new (Adobe) CFF engine
  to handle Type 1 fonts also, thus greatly improving the
  rendering of this format. This is the new default. The old
  engine is still available if the configuration macro
  `T1_CONFIG_OPTION_OLD_ENGINE' gets defined; using the
  `hinting-engine' property of the `type1' driver module you can
  then switch between the two engines.

• A new function, `FT_Set_Named_Instance', can be used to set or
  change the current named instance.

• Starting with this FreeType version, resetting variation
  coordinates will return to the currently selected named
  instance. Previously, FreeType returned to the base font (i.e.,
  no instance set).

cc katayama_hirofumi_mz, AmineKhaldi