Add mode 7 background floors and create a grass theme

[SilverCoin1719]

Adds mode 7 background that use shaders to project a square texture onto a floor in the background. Using this I created a test grass theme using some sprites I borrowed from legacy 127. The background image still needs set up properly with the layers as it's just using the preview from 127. The recommended images from me are an image that is 512x512 at scale 2 in the shader params. I don't recommend touching the other parameters in the shader as those are fairly fine tuned to the perspective. I also fixed up the grass textures so they'll be easier to implement later on.

[SilverCoin1719]

Oh one last thing the sky is still night in the grass theme, that should probably be changed

[SilverCoin1719]

made the sky daytime now, fixed the background not looping correctly as well