Jnygaard npot ap

Works by upscaling the rgb image to a power of two size *if it is not of this kind*. I.e., if it is already "power of two", it should not be rescaled. Directions x and y are handled independently, seems that WebGL textures need not be square even if power-of-two in width and height...

Upscaling done with document.createElement('canvas').getContext('2d').drawImage(...), have no idea how it does what it does, filtering-wise...