Use shared libft2 with new libpng/zlib deps.

FreeType now depends upon libpng and zlib. While I'm adding those
dependencies, I might as well also switch libft2 to a shared
library...

Bug: 9603326
Change-Id: Ibe45c186f0c933fbecebbeffc2d990b4e99d913f
Merge tag 'tags/android-4.4_r1' into kitkat-staging

Android 4.4 Release 1.0