ZENGINE: Create function for mixing two RGB<555> colors
ZENGINE: Rename Point template class to Vector2

Also remove templating
ZENGINE: Create method to get RenderTable object pointer from RenderManager

Remove passthrough methods
ZENGINE: Move generating the RenderTable to outside setRenderState

This allows the panorama/tilt options to mutated without having to generate the table multiple times.
ZENGINE: Create class for ActionDelayRender
ZENGINE: Create methods for altering panoramaOptions and create console commands for them
ZENGINE: Fix closing braces on generateTiltLookupTable
ZENGINE: Change default panorama FoV to 27 degrees

This is to match Marisa Chan's implementation. Images at this FoV also look better.