media-libs/ptex: New package

media-libs/ptex: New package

Ptex is a texture mapping system developed by Walt Disney Animation
Studios for production-quality rendering:

- No UV assignment is required! Ptex applies a separate texture to
  each face of a subdivision or polygon mesh.
- The Ptex file format can efficiently store hundreds of thousands
  of texture images in a single file.
- The Ptex API provides cached file I/O and high-quality filtering:
  everything that is needed to easily add Ptex support to a
  production-quality renderer or texture authoring application.

Gentoo-Bug: 573444

Signed off by: Jonathan Scruggs (j.scruggs@gmail.com, irc: Dracwyrm)
Signed off by: Adrian Grigo (agrigo2001@yahoo.com.au)
Closes: https://github.com/gentoo/gentoo/pull/2531

Signed-off-by: David Seifert <soap@gentoo.org>