Enable libgltf on windows as well

Change-Id: Id878bacc86facba34f77bde2fbbfd78b0a426c39
libgltf: Make it link with freetype on Windows.

Change-Id: I57dcde58bb017ab087908154bc4a1af6d5d152b9
gltf: Trying to re-create the temp path fails on Windows.

Change-Id: I30a5e1f5d09458beeb06479337b83f8479d861b5