MGL does not honor texture change

[conversy]

This issue is for the record: it was impossible to change textures between two draw calls.
I have a fix now in the glReadPixels branch : 8ed2201

The interested bits are here:
8ed2201#diff-53869c6b718c68a2c6e310b9c365722b67309d9e91c1aad12163de25965e16dcL2431-R2434

After:
RETURN_FALSE_ON_FAILURE([self bindActiveTexturesToMTL]);
I added:
RETURN_FALSE_ON_FAILURE([self bindTexturesToCurrentRenderEncoder]);

I hope this is correct and what's intended.

[darkaegisagain]

Ok, I will take a look.