NORSPEC-189 return to inefficient material update reg to avoid crashes from brundlefly solution with old reg and new callback

NORSPEC-152 better default norm/spec textures which read better in the UI and provide better default spec feedback

NORSPEC-183 fix regression in diff map blank texture from NSPEC 152 fix by forcing new BlankImageID to the old default

NORSPEC-151 NORSPEC-152 fix handling of disable of bumpy and shiny in graphics panel to also disable deferred properly and add hooks for default norm and spec textures in texture picker

NORSPEC-178 NORSPEC-179 NORSPEC-180 made enable/disable handling more consistent and increased max range on repeats per meter

Refactor LLPanelFace to make it clearer that the material is a property of the face(s) and never the panel