Draft document-rendering tiling API to be called from viewer apps

[Tor Lillqvist]

http://stackoverflow.com/questions/4593951/can-we-use-non-power-of-2-textures-on-opengl-es-on-android

So apparently if one uses OpenGL ES 2.0, there is NPOT support. Not
necessarily in OpenGL ES 1.0 (might be present on some devices as an
extension). But do we want to use OpenGL ES 2.0, I can't really see
programmable shaders being of much use to an app like this?

--tml