Support Cem Yuksel's HAIR Format

[CaffeineViking]

Most research papers on hair rendering use Cem Yuksel's HAIR file format for the geometry, since there is a large repository of existing hair styles provided in: http://www.cemyuksel.com/research/hairmodels. Write a basic HAIR file loader, more-or-less like cyHair, but optimize the file IO (uses C-style freads), and interface.

Usage:

vkhr::HairStyle curly_hair { "share/style/wCurly.hair" };

if (!curly_hair) {
    std::cerr << "Failed to load hair style!" << std::endl;
    return -1;
}

for (auto vertex : curly_hair.vertices) {
    // Do some processing on the vertices.
}

curly_hair.save("share/style/wCurly.hair.pre-processed");

if (!curly_hair) {
    std::cerr << "Failed to save hair style!" << std::endl;
    return -2;
}